Basiliscus was Eastern Roman emperor from 9 January 475 to August 476. He became magister militum per Thracias in 464, under his brother-in-law, Emperor Leo I. Basiliscus commanded the army for an invasion of the Vandal Kingdom in 468, which was defeated at the Battle of Cape Bon. There were accusations at the time that Basiliscus was bribed by Aspar, the magister militum; many historians dismiss this, instead concluding that Basiliscus was either incompetent or foolish for accepting Vandal King Gaiseric's offer of a truce, which the latter used to construct fireships. Basiliscus's defeat cost the Eastern Empire 130,000 pounds (59,000 kg) of gold, causing the empire to hover above bankruptcy for 30 years. When Basiliscus returned to Constantinople, he sought refuge in the Hagia Sophia. His sister, Empress Verina, secured him a pardon and he left the church to retire in Neapolis.

Leo I, also known as "the Thracian", was Roman emperor of the East from 457 to 474. He was a native of Dacia Aureliana near historic Thrace. He is sometimes surnamed with the epithet "the Great", probably to distinguish him from his young grandson and co-augustus Leo II.