The study reveals the characteristics of the documentation database compiled by Flavius Cassiodorus in 519 compilations, known as the Chronica, but represent a mixture of records and duplicates of excerpts from a number of the consular lists of the Roman Empire, the Ostrogothic Kingdom and the Byzantine Empire V – VI centuries. It is shown that the Cassiodorus̕ composition has retained all the hallmarks of the сhronicles of late antiquity. The content of the document, however, also reveals some medieval signs: attention to the calculations of the Easter cycles, fixing only particularly significant (for a particular year) events, the desire for chronological certainty of the recorded facts. The data in this document, however, are equivalent, regardless of the Roman or Ravenna origin of the facts, dates and estimates covered. The article focuses on the nature of the dependence of the text "Chronicles", covering the events of the second half of the V century., the so-called Ravenna fasti (Consular lists), which formed the basis of a number of contemporary Chronicles. The main material for showing the possible dependence of Cassiodorus ' work on these fasts is the vindobon Fasti (the Vienna manuscript), which the Senator could use independently of the Ravenna consulars. The differences in the texts of the Cassiodorus̕ "Chronicle" and Vindobonae document may indicate Cassiodorus̕ Roman Legitimist bias in the socio-political situation of the Ostrogothic Kingdom. Over time, this bias could develop into a focus on Constantinople in the conditions of the Byzantine-Gothic war.