Magnus’ Choice. The Origins of the Frisian Freedom
According to medieval legends around AD 800 Charlemagne and Pope Leo came into conflict with the city of Rome. The Pope was attacked and had to flee the city. It was an army of 'naked' Frisians headed by Magnus that retook the citadel and the eternal city. In return Charlemagne offered wealth, weapons, treasure and more. Magnus’ choice, however, was that all Frisians would be free and not subordinate to anyone else, except of course to the Holy Roman Emperor himself. Charlemagne granted this wise request and behold: the Charlemagne privileges or Magnuskerren. Choices that even have implications for today who has to pay taxes and who not!
The Magnuskerren have many names, in many languages, like: Magnuskeuren, Karelsprivileges, Karlsprivileg, Friesische Freiheit, libertas Frisonica or Previlegii Frisiorum Caroli Magni. For the Frisians these privileges were the legitimation that the free-farmer republics of Frisia of the High Middle Ages, then stretching from the region Westfriesland (province Noord Holland) in the Netherlands to the River Weser in Germany (and sometimes even the non-Frisian region Dithmarschen was included), were not to recognize anyone as their lord. In other words: the Frisians claimed to be Reichsunmittelbar since the rule of Charlemagne.
And kas, that Fresan friheren were, thi berna and thi onberna, also lange so thi wind fan tha olcnum we, and thio wrald stode, and wellat wasa mith tha kere thes koninges hacha heranatan.
And [he] chose that all Frisians freemen were, the born and the unborn, as long as the wind blows from the clouds, and the world stands, and with this choice they want to be the king’s high men.
A 'ker' from Magnus-kerren is related to the current Mid-Frisian word 'kar' which means choice. 'Kerren' is plural.
At beginning of the High Middle Ages, the southern coastal zone of the North Sea had undergone an opposite development compared to the rest of Europe. Instead of developing feudal structures with government institutions, Frisia ‘returned’ to you could say the Germanic tribal society. Around AD 1100 this defragmentation process was completed in Frisia between the River Lauwers in the Netherlands and the River Weser in Germany. Besides Frisia, also the Saxon region of Dithmarschen underwent the same development. When in AD 1101 the Saxon Henry the Fat became Margrave of Frisia, the Frisians (probably of current region Ostfriesland) killed him immediately during his first visit to Frisia in an attempt to claim his rights, his gift. A clear statement of the Frisians no foreign authority was accepted anymore (by the way, AD 1101 is the same year Count Floris the Fat of West Frisia renamed himself Count of Holland). The process of defragmentation and the shrinking of external influence (i.e. the bishopric of Utrecht) in the part of Frisia what's today province Friesland in the Netherlands, took about one and a half century longer than the rest of Frisia.
Anyway, the result was that in the High Middle Ages every terp (artificial settlement/dwelling mound, mostly found at the tidal marshlands along the Wadden Sea), every village, every farmer was basically free. No obligation to fight for any foreign lord except for the emperor, and then only limited to defend the territory of Frisia. Nor any obligation to pay taxes to counts and bishops alike. Having the right of possession too. Having the right to uphold their own laws and, moreover, to choose their own redjevas 'judges'. Concerning those chosen judges, the name used in the sagas of the Charlemagne privileges is potestas frisae. This title and office was unknown in the wider region of north-western Europe, but was similar to the thirtheenth century AD office of podestà in Italy. In the Italian city republics this was a chosen office of justice/judge and at the same time that of commandor during war.
Of course, the feudal and religious powers surrounding Frisia both close and from afar thought quite the opposite with regard to the Frisian Freedom. It were for example the thirteenth century AD writers Melis Stoke (province Zeeland, the Netherlands) and, especially, Jacob van Maerlant (Flandres, Belgium) who were openly annoyed by this so-called Frisian freedom. Needless to say, they fully supported the claims of the counts of Holland on Frisia.
From the late eighth up to the eleventh centuries AD the Frisians were leading in the supra-regional trade in north-western Europe. These merchants traded for personal benefit and on individual basis mainly. Not under the authority of an ecclesiastical or a worldly power. All very much evolving from the fully decentralized structure of the Frisian society. A genuine free trade. The connotation 'Frisian trade' even became synonymous to 'overseas trade'. Read our blog post How the porcupine gave birth to the US buck to get an idea of the volume of this free trade avant la lettre. You might say, in this regard the Frisian Freedom built upon an old tradition.
But what’s true of these Magnuskerren? Let’s start where it all began: the eternal city. We take you to one of the old churches in Rome, the Church of the Frisians (or Friezenkerk or Friesenkirche). Only a stone’s throw from the magnificant Saint Peter’s Basilica. Less than 100 meters to the Saint Peter's Square.
Presence of the Frisians in Rome actually does date back to the time of the Magnus sagas. The oldest mention is of the Frisian schola in AD 799 when the schola welcomed back to the city Pope Leo III, who had lived in exile for six months in Paderborn in Germany. Scholae existed for the Saxons (schola Saxonum), the Franks (schola Francorum), the Lombards (schola Langobardorum) and the Frisians (schola Frisonum), and were established after these tribes had been Christianized. The schola Frisonum was the latest addition of the four, because initially the Frisian stayed at the schola of their neighbours the Saxons. The schola Frisonum is also mentioned in the Liber Pontificalis 'Book of the Popes'.
Church of the Frisians
with Saint Peter's Basilica in the back
A schola was a walled place where pilgrims could stay and where they had their own church, hospital and cemetery. The exception was the Saxons who used their own language to indicate a schola, namely burg. Today, the medieval city district Borgo, or I Borghi, still reminds of this old Saxon name. The Frisian schola was built on Janiculum Hill, 500 meters from the River Tiber and overlooking the Grave of Saint Peter at the Vaticanum. The Vaticanum was the name of the level area between Vatican Hill and the River Tiber, and also known as Nero's Plain.
The name Janiculum Hill is a reference to the pagan god Janus that was once worhshipped. Janus had two faces. One looking to the past and one looking to future. The god of all beginnings and of passage. Hence the month January. And images of Janus must have been present on this hill. There's a Janus head to be seen in former Frisia as well. No kidding. Not on a hill top but -what else?- on top of a dike, at the town of Harlingen in the Netherlands. Errected in AD 1576, it's the landmark to mark the end of long disputes between five districts about the maintenance of sea dikes. On top of the stone pilar a two-faced Janus head is placed. It's nickname is the Stenen Man 'man of stone'. Now we would name him super-hero 'The Thing'. Harlingen will appear again in this blog post, see below.
Back then you walked up the Janiculum Hill via a path called Vicus dei Frisoni, also named Borgo dei Frisoni. Everything was outisde the medieval city walls of Rome, until AD 848. In this year the Vaticanum level area was included within the walls. Later in the sixteenth century AD, on the Vaticanum, the grand Saint Peter Basilica as we know it today, was built. Therefore, today the Church of the Frisians overlooks the impressive Saint Peter’s Square. A prime location. Furthermore, every schola also had its own militia to defend the schola. Pilgrims could join these militias. It were these militias that welcomed Pope Leo III in AD 799. Another option as pilgrim or soldier was to settle as farmer. The Frisians and the Saxons did that in the valley of Crepacore and near mountain Capricore, 40km north of Rome as the crow flies. The villages there also had there own militias called militiae rurales Sancti Petri.
Saint Peter's Basilica with Circus Nero projected (green).
Right-mid/below the Chruch of the Frisians (San Michele in Sassia)
The name Nero's Plain (Vaticanum) for the level area outside the old city of Rome stems from Emperor Nero. On the spot where Saint Peter's Basilica stands today, stood the Circus of Nero before. The circus was built in the first century AD. It's the same circus where to two Frisian kings Verritus and Malorix enjoyed watching the hunger games avant la lettre in the year AD 58. Both kings had been received by Emperor Nero personally to listen to their plead for the (continious?) use of arable land adjacent to the limes (Roman border fortifications) along the River Rhine. Read more about these two Frisian kings in our blog post Celtic-Frisian heritage: There's no dealing with the Wheel of Fortune.
Because of the Investiture Controversy, in AD 1084 the Holy Roman Emperor Henry IV besieged Rome and installed antipope Clement III. Desperate Pope Gregory VII asked the Norman (or Viking, if you like) Robert Guiscard to help out. He did. Henry IV had to retreat, and Pope Gregory was back in the saddle. It came with a very hefty price, though. Consistent with Viking traditions Guiscard’s army sacked most of the city, including the scholae of the Frisians, the Franks etc. All Frisians were killed as well. Only two things remain today from the schola Frisonum. That's, firstly, a Latin grave inscription HEBI GENE FRISONO ‘Hebe or Hebbe of the Frisians’ who died there in the year AD 1004. Possibly a knight. The second thing that's still there to be admired, is the well. It's behind the Church of the Frisians, in the garden of the fathers Jesuits.
Church of the Frisians, Vatican City
engr. by Frisian artist M.C. Escher
At the spot of the former schola and church, the Frisians built the Church of the Frisians which was consecrated in the year AD 1141. Its Romanesque bell tower, which stayed more-or-less unchanged ever since, is even the oldest of Rome. And although for some decennia the tower was mute, since this summer the tower bells casted in the eighteenth century AD have been restored and the church has joined the cacophony of ringing towers of Vatican City and Rome again. Other names for the church are San Michele dei Frisoni, San Michele in Sassia and Santi Michele e Magno. The church was therefore dedicated to Archangel Michael, the first patrocinium of the church. Indeed, the great artist and architect Michelangelo received his name from this angel too, and he's also famous for painting the Sistine Chapel ceiling of the nearby Saint Peter's Basilica. Archangel Michael, however, was the leader of the army of God against evil, angel of death and responsible for weighing the souls after death. Therefore, Archangel Michael was associated with justice and righteousness too. The latter aspects correspond with the former Frisian pagan god Forseti, a god of justice too and worshiped at the North-Frisian island Heligoland in the north sea and in southern Norway. However, in general, the Germanic god Wodan/Odin was replaced by the archangel Michael after christianization. But, a second patron for the church was coming up: Saint Magnus.
Saint Magnus is being worshiped in the towns of Fondi and Anagni in the region Lazio in Italy and churches are dedicated to him. Other churches in Europe dedicated to Saint Magnus are up north. Firstly, this is the church of Esens in the shire Harlingerland in Ostfriesland (East Frisia), Germany. Secondly, these are the churches of the villages of Bellingwoude in province Groningen and of Hollum and Hoornsterzwaag both in province Friesland (Mid-Frisia) and of the church in the village Anloo in province Drenthe, in the Netherlands as well. In sum, Frisia and Italy. Now how did that all happen?
For this we turn to another, lengthier inscription preserved in the Church of the Frisians in Rome. To see it, go to the back of the church and look for it above a door at the left. It's the story about three Frisian soldiers serving in Charlemagne’s army and who are on their way back to Frisia after a military campaign against the Saracens (i.e. the Muslims from northern Africa) in the region Apulia in the southeast of Italy. Their names are Ilderado from Groningen, Leomot from Stavoren and Hiaro from Slinga (unclear where the village Slinga was located, see further below). It’s then that the three men find the dead body of Saint Magnus. Magnus was a martyr and bishop of the Roman Period, in the third century AD. No explanation is given as to why the body is there. The men decide to take the body to Frisia. When they are near the town of Sutri, north of Rome, the body refuses to be taken any further. In their dreams the men were told to bring the body to their church in Rome. So, they did. And the Church of the Frisians got its second patrocinium and hence its double name, Michael and Magnus.
Because of the three man’s devotion they were allowed to remove a part of the arm of Saint Magnus to serve as a relic back home in Frisia and pieces of the arm were apparently spread over the villages of Anloo, Bellingwoude, Esens, Hollum and of Hoornsterzwaag. How relics, if they did, ended up from the church in Rome in the churches of Anagni and Fondi, is not told.
Because the full text of the inscription isn't easily accessible on the web, it’s presented below for the non-believer or simply the connoisseur, with a translation (Verweij, 2014). The tekst is full of abbreviations so hard to read.
IN NO DNI TEMPORE LEONIS IIII PP IPATE CARVLO MAGNO IPATORE EO TEPORE QVO PETRI BASILICA A SARRACENIS CAPTA FUERAT, TVNC DENIQ P TOTIVS MVNDI CAPITE TVRBATO TOTVS MVNDVS TVRBATVS OMIS GALLIA CV REGE CARVLO AD TVENDV ILLA VENERVNT. VNDE CNTRA INIMICOS DNI BELLA DNI DECERTANDO QDAM MORTVI S ET IN CRIPTA IVXTA NERONIS PALATIVM SEPVLTI, EODD TEPORE A LEONE PP ET REGE K AD HONORE MICHAELIS ARCGLI SUP ILLOS FACTA EST ECCLA. HIS ITA PACTIS REX APVLIA ABIIT EAQ BEATO PETRO ET ROME SVBIVGAVIT. P IDE TEPVS EXERCITV GALLIA REVERTENTE TRES ILLORV MILITES DE FRISIA ILDERADO DE GRONINGA ET LEOMOT DE STAVERA ET HIARO ET CELDVI ANCILLA DEI DE SLINGA. HI BEATI MAGNI CORPVS IN LOCO Q DICIT FVNDI INVENER. QVO INVENTO IN ILLORV PVINCIA PORTARE ET CDIRE DECREVER SED DIVINA GRA COHOPANTE POSTQVA AD SVTRINAS PARTES VENT E APLIVS DEFERRE N PVALVER QA BIS ET TER TERRITI ET P SONIV MONITI ROMA REVERTENTES SCVM CORP SECV TVLER VNDE FACTV E QVOD ILLORV DEVOTIONIS CAVSA PARTE BRACHII A SE SEGREGARI AB ILLIS PMISIT. PARTES AVTE CETERE IN CRIPTA PFATA REMANSER SUP QVA SICUT DICTV EST ECCLA IA FVERAT FACTA DEINDE OMNI ANNO SIMVL BENEFICIV OPTIMV DARI IBI DECREVER SCILICET TRECENTAS MARCAS ARGENTI P ILLORV ET VBIQ REQESCENTIV REDEPTIONE ET IM PERPETVV SEV DIVITES SIVE PAVPERES IN EADE SVPRA DICTI ARCHANGELI BASILICA ET BEATI MAGNI ECCLA IVXTA EA AB EISDE CONSTRVCTA HOSPITALIA QVANDO A SVIS PARTIBVS VENIRENT AGERENT. IDCIRCO NROR ALIORVQ OMIB PATEAT SI IPSI VEL QCVQ HOC DECRETV RVPE TEPTAVERINT SCIANT SE PPETVO DAPNATOS ET MALEDICTOS ET PREDICTI PONTIFICIS ANATHEMATIS VINCVLIS IN INFERNO NISI RESIPVERINT CV DIABOLO CLIGATOS, IN HAC AVTE VITA MISEROS PAVPES ET DISPSOS ET ITERV DE LIBRO VITE CELESTIS DELETOS ET DE REGNO XRI DEIECTOS. CONFIRMATORIB FAVTORIB HVI DECRETI EC TR SIT BENEDIC XRI ET FRVANT VTRIVSQ VITE GAVDIIS AM
In the name of the Lord. In the time of Pope Leo IV when Emperor Charlemagne was emperor, at that time when Saint Peter's Basilica was taken by the Saracens, when finally, the whole world was confused, all of Gaul came with King Charles to protect her. When a few died fighting with the Lord's war against the Lord's enemies and were buried in a crypt next to Nero's palace, Pope Leo and Charlemagne in honour of Archangel Michael built a church above them. When all this was done, the king went to Apulia and submitted it to Saint Peter and Rome. At the same time, when the army returned to Gaul, three soldiers from Frisia, Ilderado from Groningen, Leomot from Stavoren and Hiaro and the maidservant of the Lord Celdui from Slinga, found the body of Saint Magnus in the place called Fondi. When they found this, they decided to carry it to their region and bury it there, but with the help of God's will they could not carry [the body] any further after they had come close to Sutri. They were frightened two or three times and warned in a dream, they returned to Rome and brought the body with them. Because of their devotion [the Pope] allowed them to separate part of his arm from the body. The other parts, however, remained in the above crypt above which, as stated, a church was already built. Then they decided that every year a very great gift would be given, namely three hundred marks of silver for the redemption of themselves and for those who rested there, so that for ever rich or poor would stay in the aforementioned basilica of the archangel and church of Saint Magnus in the hospital they built next to it, if they came from their regions. That is why it is clear to all of us and to everyone else that if they try to break this decision, they must know that they will be condemned and cursed forever and will be bound by the anathema of the aforementioned pope with shackles in hell and sit together with the devil unless they come to their senses, and will be miserable, poor and scattered in this life, and will be nullified from the book of heavenly life and expelled from the Kingdom of Christ. For those who confirm and favour this decree, etc. blessed by Christ and may they enjoy the joys of both lives. Amen.
The dating of the inscription is not very precise. The inscription itself talks about Charlemagne and Pope Leo IV and the time the Saint Peter’s Basilica was sacked by the Saracens. That points to the year AD 848 when the Saraceni attacked Rome and were defeated by Germanic armies, including the Frisians. In that same year the Saracens were chased all the way south to Apulia. Charlemagne, however, couldn’t be part of this history, since he was already dead by the time Leo IV was pope (AD 847-855). Besides, if AD 848 is indeed the correct year of the story, it means Pope Leo was dead by then too. Anyhow, based on the ‘financial’ passages of this inscription concerning the gift, scholars date the inscription itself the first quarter of the eleventh century AD. Thus testifying about events which took place almost two centuries before.
So, now we have the ingredients. Saint Magnus, Frisians in Rome, Charlemagne, fightings against the Saracens, and Archangel Michael. Take a blender and press on button 3 for a maximum effect to create the saga of the Frisian Freedom. Or as they said back then: 'fry ende freesk' (free and Frisian) or 'fry freesk' (free Frisian), a slogan dating back to the eleventh century AD (Vries, 2012).
This is the smoothie you get:
In all the different versions of the Magnus saga the Frisians fight against the citizens of Rome, the Saxons and the Saracens, or a combination thereof, and always to free Rome for the sake of Charlemagne and the Pope. Besides this, the Frisians supposedly fought like true biblical Urías in the frontline and under command of their leader Magnus who carried a red banner. Apparently Saint Magnus was transformed from an Italian bishop into a Frisian warrior. Also, the Frisian warriors are described as ‘naked’ in the sagas, what's meant by that they didn’t wear (heavy) armour and helmets. This corresponds with the images preserved of high-medieval, barefooted Frisian warriors: read our blog post Foreign Terrorist Fighters from the Wadden Sea. Lightly armed and fast in charging at the enemy. Even their hair shaved off. All versions of the saga also have in common that the Frisians were rewarded for their heroic deeds and achievements by Charlemagne himself. Sometimes the freedom was pro-actively given to them, although mostly it was chosen by their leader Magnus: the so-called Magnuskerren. And the Magnuskerren were laid down in a charter together with a seal of Charlemagne and brought to Frisia by Magnus together with the red banner.
The saga of the Frisian Freedom, with different accents, has been codified in several Old-Frisians law books: Codex Unia (U), ca. AD 1650; Scripture of Fivelgo (F), ca. AD 1450; Jus Municipale Frisonum (J), ca. AD 1530; Druk (D), ca. 1485; First Hunsingo Codex (H), early fourteenth century AD; Codex Aysma (A), sixteenth century AD.
To makes things more credible a serious Magnus pedigree was constructed too. He received a totally fictonal genus name, namely Forteman. And he got his own seal. Furthermore, Magnus Forteman supposedly was the first duke of Frisia. And while they were at it, and why not?, his father Gustavus founded the first church in Frisia, at the village of Harlingen. The church at Harlingen, originally built around the year AD 1200, has Saint Michael as patron. Also, the coat of arms of Harlingen carries the image of Saint Michael.
The present-day town of Harlingen developed from the terp settlement of Almenum. On this terp stands the church of Saint Michael. The name Almenum -still being used- might indicate a pre-Christian origin of a temple or sanctuary at this spot. The morpheme 'al' stems from 'al(a)h' meaning temple and 'alhist' meaning 'dwelling near the temple'. Other place names in the Netherlands with a similar origin are Aalst and Elst. Other morphemes that point towards a spot of pre-Christian sacral relevance are 'harg' (hill, elevations, pile of rocks) like the villages of Hargen in province Noord Holland and Harich in province Friesland and 'wîha' (sanctuary) like Wehe-Den Hoorn in province Groningen and Wijhe in province Overijssel and Wije in province Gelderland. Old English had similar names, namely 'hearg' and 'weoh' which can be found in the epic poem Beowulf.
There's even a theory that Hiaro of Slinga, one of the three soldiers who find the body of Saint Magnus (see above, the inscription in the Church of the Frisians in Rome), is actually from Hlinga. The 'S' of Slinga would be a slip of the chisel, which in turn stems from Harlinga and thus Harlingen. Together with a thirteenth century AD seal from shire Wonseradeel in province Friesland, which depicts a warrior with the eagel of Charlemagne (possibly indeed Hiara from Slinga) and bearing the text Sanctus Magnus dux Frisonum 'Saint Magnus duke of Frisia', a fusion was made of the historic persons Hiaro and Magnus (Van Buijtenen, 1953). We are, however, not sure simply another saga has been created with this 'theory'. It needs quite a lot brain gymnastics, to be frank. And how to incorporate the older place name Almenum, we do not know either, based on this creative outburst of Van Buijtenen).
seal of Magnus Forteman
Of course, the whole early-medieval story about the Magnuskerren and Magnus is fake news. Still, it constituted a crucial part of high-medieval Frisian society to withstand the claims of non-Frisian, feudal and ecclesiastical rulers to incorporate Frisia into their jurisdiction. As said earlier, Frisia was a collection of countless free-farmer republics and its defence fully relied on people, on citizens, on farmer militias. These legends and sagas helped to motivate and organise themselves. Nowadays, the Mid-Frisians would call that mienskip. The many little republics were loosely united within the almost mythical but beautiful named saun zelanden ‘Seven Sea Lands’. Later, at the beginning of the thirteenth century AD, the small republics tried to strengthen their alliance with the Upstalsboom treaty. The Upstalsboom had its own seal (too) with an image of Charlemagne sitting between two Frisians warriors. The man, Charlemagne, keeps popping up. When the Frisians and their chosen judges gathered at the hill of the Upstalsboom once a year on Pentecost, the motto spoken was eala Frya Fresena 'stand up/hail free Frisians'. The alliance of Upstalsboom failed ingloriously, however. Read our blog post Upstalsboom: why solidarity is not the core of a collective to know why.
But, there might be some truth in it after all.
In AD 1234 William II, son of Count Floris IV of Holland, became the new count of Holland and Zeeland (i.e. most of former West Frisia). In AD 1248 Count William fought against the excommunicated Emperor Frederick II and conquered among other things the city of Aachen. Curiously, it were Frisians who fought under his banner. The same year, William II was crowned as Holy Roman Emperor. Two days after his coronation in the Aachen Cathedral he gave priviliges to the Frisians who were gathered in the cathedral too! Actually, William II reconfirmed -in a charter- the rights, freedoms and priviliges that Charlemagne already had given to the Frisians. So, Emperor William made a connection again with Charlemagne and that era.
Whatever the privileges for the Frisians, the Westfriesen of current region Westfriesland (province Noord Holland in the Netherlands), who were in a bitter conflict with the sutherna here 'southern lords' (i.e. counts of West Frisia/Holland) for centuries already, slaughtered William II without hesitation in the cold winter of AD 1256 when he was on a military expedition in region Westfriesland. Read also our blog post In debt to Westfriesland about the history of the free-farmer republic Westfriesland and their struggle with the counts of West Frisia/Holland.
Then, in the winter of AD 1417 Holy Roman Emperor Sigismund extended (again) to universorum Incolarum et inhabitantium tam Orientalis quam Occidentalis frisie ‘all people and inhabitants of East and West Frisia’ the freedom privileges for real. Although not from Charlemagne, still from an emperor. The charter with a big seal has been preserved. Despite Sigismund’s generous ruling the Frisians do pay taxes to the German and Dutch governments today. Maybe they should make a case at court with Sigmund's charter as their inalienable right. They even might challenge Benjamin Franklin's quote that nothing is certain in life but death and taxes!
copy of freedom privileges of HRE Sigismund, AD 1417
at the House of Province Friesland
Parallel to the decline of Frisia, the Church of the Frisians in Rome fell into disuse in the Late Middle Ages and the Chapter of Saint Peter took possession of the church. But when you're in Rome to visit the Church of the Frisians, do not forget to take a look at Saint Peter Basilica too. It's worth it.
Note. The East Frisians have a diffrent legend as to how they received their freedom. That was after the battle of Norditi in AD 884, also known in Germany as the Normannenslacht. It was a battle (some argure several battles) between the Frisians and the Danes who had occupied the coastal zone of East Frisia. As a sign of gratitude for pushing out the Vikings, King Charles the Fat gave the Frisians their freedom.
Suggestion for further reading:
Abernethy, S., The schola Saxonum and the Borgo in Rome (2019)
Blok, P.J., De Friezen te Rome (1902)
Bremmer, R.H., "Thi Wilde Witsing": Vikings and Otherness in the Old Frisian Laws (2020)
Eijnatten, van J. & Lieburg, van F., De Nederlandse religie geschiedenis (2005)
Folkerts, R., Die Theelacht zu Norden. Ein seit 1100 Jahren auf genossenschaftlicher Basis geführter Familienverband (1986)
Israel, J., Friesland and the Rise of Democratic Republicanism in the Western World (1572-1800) 2019
Molen, van der S., Oorsprong en geschiedenis van de Friezen (1981)
Muskens, M.P.M., De Kerk van de Friezen bij het Graf van Petrus. De geschiedenis van de kerk. De kerk in de geschiedenis (1989)
Schuyf, J., Heidense heiligdommen. Zichtbare sporen van een verloren verleden (2019)
Tuuk, van der L., De eerste Gouden Eeuw. Handel en scheepvaart in de vroege middeleeuwen (2011)
Verweij, M., De zusterkerk van Anloo: de SS. Michele e Magno te Rome, Magnuslezing (2014)
Vries, O., Asega, is het dingtijd? De hoogtepunten van de oudfriese tekstoverlevering (2007)
Vries, O., De taal van recht en vrijheid. Studies over middeleeuws Friesland; Die Friesische Freiheit; ein Randproblem des Reiches; De Aldfryske pearformule fry ende freesk (2012)