Pope John I (Latin: Ioannes I) was Pope from 13 August 523 to his death in 526. He was a native of Siena (or the "Castello di Serena", near Chiusdino), in Italy. He was sent on a diplomatic mission to Constantinople by the Ostrogoth King Theodoric to negotiate better treatment for Arians. Although relatively successful, upon his return to Ravenna, Theodoric had the Pope imprisoned for allegedly conspiring with Constantinople. The frail pope died of neglect and ill-treatment.