[ΠΡΟΚΟΠΙΟΥ ΚΑΙΣΑΡΕΩΣ] Procopii Caesariensis: Ανέκδοτα Arcana Historia. Lyon 1623 EDITIO PRINCEPS in Greek. In folio (30 × 20 cm). Contemporary full vellum with manuscript title on spine; very light wear. Complete: [12], 24, 136, 142, [20]; [103], 304, [26], 171 pp. Greek original with facing Latin translation, extensive scholia in Latin. Paper slightly browned, otherwise in very good condition. Procopius (c. 500–after 565) was a prominent Byzantine scholar, often regarded as the last great historian of the ancient world. His Secret History (Ἀνέκδοτα) reveals the hidden realities of 6th-century Byzantine politics and society, claiming to expose the private intrigues of the ruling class. Today it is highly valued as a major historical source. The work was discovered only in the early 17th century in the Vatican Library and published here for the first time in 1623 by Nicolaus Alamanni. Its publication greatly transformed the understanding of mid-6th century Byzantine society and history.