It is also thought to be the earliest example of a document written in English, or indeed in any form of a surviving Germanic language, though extant only in an early 12th-century manuscript, Textus Roffensis.

The code is concerned primarily with preserving social harmony through compensation and punishment for personal injury, typical of Germanic-origin legal systems.

[3]: 22  He was responsible for commissioning copies of the Anglo-Saxon Chronicle at Canterbury Cathedral Priory and Peterborough Abbey, as prior and abbot respectively.

[3]: 22–23 Francis Tate made a transcription of Textus Roffensis c. 1589, which survives as British Museum MS Cotton Julius CII.

[3]: 251–256  Notable examples include: In 2014, Rochester Cathedral and the John Rylands University Library of Manchester cooperated to make the complete text available online in facsimile.

[9] Legal historian Patrick Wormald argued that it followed a model from the 614 Frankish church council in Paris, which was attended by the abbot of St Augustine's Abbey and the bishop of Rochester.

[5]: 97–99 Patrick Wormald divided the text into the following sections (the chapter numbers are those in Frederick Levi Attenborough's Laws of the Earliest English Kings and in Lisi Oliver's Beginnings of English Law):[10][3]: 60–81 [4]: 3–10 Another legal historian, Lisi Oliver, offered a similar means of division:[3]: 36 In addition to protecting church property, the code offers a fixed means of making social conflict and its escalation less likely and ending feud by "righting wrongs" [Wormald].

[3]: 25–34  For instance, it uses an instrumental "dative of quantity" [Oliver] that is obsolete in later Old English grammar: Gif friman edor gegangeð, iiii scillingum gebete ("If a freeman enters an enclosure, let him pay with 4 shillings").

[3]: 32, 42  As another example, in the apodosis the verb is always in the end position in Æthelberht's law; while this is grammatical in Old English, it is an archaic construction for a legal text.

[3]: 31 Words such as mæthlfrith ("assembly peace") drihtinbeage ("lord-payment"), leodgeld ("person-price"), hlaf-ætan ("loaf-eater"), feaxfang ("seizing of hair") and mægðbot ("maiden-compensation") are either absent in other Old English texts or very rare.

[3]: 91–93  Doubling vowels to indicate length (for instance, taan, "foot"), common to all written insular languages in the early Middle Ages but increasingly uncommon later on, occurs three times in Æthelberht's code but not elsewhere in Textus Roffensis.