Lex Frisionum, a "Law program of the Frisians", was recorded in Latin during the reign of Charlemagne, after the year 785, when the Frankish conquest of Frisia was completed by thedefeat of the Saxon rebel leader Widukind. The law code forwarded the region of the Frisians.
On numismatic grounds based on the amounts of fines compositio and wergeld, the laws from the Lex Frisionum date from the number one half of the 7th century at the latest.
There are no surviving manuscripts of the Lex Frisionum. The only testimony is the oldest printed version, which dates from 1557. In that year, the scholar Joannis Basilius Herold portrayed a compilation of all Germanic laws from the time of Charlemagne, Originum ac Germanicarum Antiquitatum Libri..., printed by Heinrich Petri of Basel. Among them was printed the Lex Frisionum, but from what source, or how corrupted was Herold's text, is unknown; the title-page of his edition indicates that the material was drawn from the library now dispersed of the monastery of Fulda.
The surviving explanation is apparently a rough draft, still retaining pagan elements, which doubtless would pretend been edited out in the finished version, which Charlemagne apparently contemplated assembling for each of the Germanic peoples in his empire.