The Liber covers the period from the founding of the abbey in 673 until the middle of the 12th century, building on earlier historical works.

The longest of the contemporary local histories, the Liber chronicles the devastation that the Anarchy caused during the reign of King Stephen.

Other themes include the miracles worked by the monastery's patron saint, Æthelthryth, and gifts of land to Ely.

The Liber Eliensis provides an important history of the region and period it covers, and particularly for the abbey and bishopric of Ely.

[5] Janet Fairweather, a classicist and a recent translator of the Liber, suggests that it may have been written by someone other than the traditional candidates.

Those from the south, including the Liber Eliensis, mainly concern themselves with the various controversies involving their respective religious houses.

Lesser-used sources include the Anglo-Saxon Chronicle, Orderic Vitalis' Historia Ecclesiastica, Stephen of Ripon's Vita Sancti Wilfrithi, William of Malmesbury's Gesta pontificum Anglorum, a list of the kings of Wessex, the Old English poem The Battle of Maldon, and a number of saints' lives, including some written by Eadmer, Felix, Abbo of Fleury, Goscelin, and Osbern of Canterbury.

The primary one of these works was Bishop Æthelwold of Winchester's Libellus, large parts of which were copied into the Liber Eliensis.

Accounts of the subsequent abbots until the last, Richard, are included in Book II, as well as numerous charters and other documents.

The work describes the area around the abbey for 20–30 miles (32–48 kilometres) as being filled with unburied corpses, and that the price of a bushel of grain rose to 200 pence.

The Liber gives a detailed account of Nigel's career, although in general the chronicle's author favours Stephen over his own bishop.

[22] The work may have helped to increase the number of pilgrims visiting Ely, as well as enabling the monks to better explain the history of earlier donations to the abbey.

[24] The historian Jennifer Paxton argues that increasing pilgrimage to the monastery was one of the main goals of the compilers of the Liber.

According to the chronicler, the division took place during the episcopate of the first bishop, Hervey le Breton, and was characterised as barely adequate for the needs of the monks.

[28] The Liber was familiar to the 13th-century chronicler Matthew Paris, who used it along with the Chronicon Abbatiae Rameseiensis of Ramsey Abbey in his own historical works.

[30] The Liber is the longest of the local histories produced in England during the 12th century,[31] and it contains a description of the royal chancery, which might be the earliest evidence for the existence of that office in the Anglo-Saxon kingdom.

The Liber describes how King Edgar (died 975) granted the abbey the office of chancellor (head of the chancery), but the authenticity of the passage is unclear.

[32] The existence of a formal chancery office in Anglo-Saxon England before the Norman Conquest is a matter of some debate amongst historians.

[34] It was written to help buttress the claims of Ely to a judicial liberty,[35] or the exercise of all the royal rights within a hundred.

[37] The historian Antonia Gransden characterises the Liber as "valuable for general history", but qualifies by saying that "the whole lacks unity and has errors and confusing repetitions".

British Library MS Cotton Titus A.i, usually known as the G manuscript, has part of Book II, and dates from the late 12th or early 13th century.

Two other related works containing just cartularies are British Library Cotton MS Tiberius A vi and Cambridge University Library Ely Diocesan Register Liber M.[42] Liber Eliensis has been published by the Royal Historical Society in its Camden Third Series, edited by E. O. Blake.

[46] Janet Fairweather has produced a recent English translation of the Latin, published in 2005 by Boydell & Brewer.