Justin I (; , "Ioustînos"; 2 February 450 – 1 August 527) was the Byzantine emperor from 518 to 527. He rose through the ranks of the army to become commander of the imperial guard, and when Emperor Anastasius died he out-maneouvered his rivals and was elected as his successor, in spite of being almost 70 years old. His reign is significant for the founding of the Justinian dynasty that included his eminent nephew Justinian I and three succeeding emperors. His consort was Empress Euphemia.