The Alexiad
Full text of Anna Comnena's Alexiad — the only major historical work authored by a woman in the medieval period, and the indispensable Byzantine account of the reign of Alexios I Komnenos and the First Crusade.
Byzantine Empire
History of the Later Roman Empire, Vol. 1
The first volume of J.B. Bury's authoritative history of the Later Roman Empire, covering the reigns from the death of Theodosius I through the accession of Anastasius — an age of barbarian pressure, dynastic crisis, and the definitive parting of East and West.
History of the Later Roman Empire, Vol. 2
The second volume of J.B. Bury's authoritative history of the Eastern Empire, covering the reigns of Anastasius, Justin I, and Justinian — including the great reconquests of Africa and Italy under Belisarius and Narses.