St. John was born in 344 in Antioch, studied under very acclaimed scholars, and developed a keen gift for rhetoric. Around 375 he dedicated his life to Christianity and became a hermit, living an extreme ascetic life which consisted of getting little sleep, constantly standing and memorizing the entire Bible. Those two years caused him serious health issues, so he was forced to return to Antioch and was eventually ordained and named Archbishop of Constantinople. St. John was known for his unapologeitc preaching, and his homilies and writings converted many pagans. Eventually he was banished due to his outspoken opposition of the worship of pagan gods, and died while in his exile. He is hailed as a great Father of the Church in both the Roman Catholic Church and the Eastern Orthodox Church.