Andrea and his brother Paolo were the founders of the Sacred Military Constantinian Order of Saint George and were papally recognized claimants to descent from the Angelos dynasty of Byzantine emperors.
[4] In 1545, Andrea and his younger brother Paolo were officially acknowledged as descendants of the Angelos emperors by Pope Paul III (r. 1534–1549).
[6] The papacy was eager to support the two brothers and their family since a Catholic family of Byzantine claimants meant the possibility of eventually restoring the Byzantine Empire as a Catholic nation, religiously obedient to the Pope.
[9] When exactly the order was founded is not clear, but Andrea is attested as using the title of Grand Master from Pope Paul III's acknowledgement of the brothers in 1545 and onwards.
[11] On his death in 1580, Andrea proclaimed his nephew Pietro as his heir "by reason of primogeniture", which ensured that his titles and position of Grand Master would pass down through the Angelo Flavio Comneno family in a hereditary manner.