Today was the feast of St. John Chrysostom, Doctor of the Church. He was born in Antioch in the fourth century, at a time when Antioch was perhaps the second most important city in the Roman empire. He was never known as 'Chrysostom' in his lifetime; 'Chrysostom' is an agnomen later conferred on him to distinguish him from all other St. Johns; it means 'Golden-mouthed'.
We don't have a very in-focus view of his life. He became deacon for Meletius of Antioch, who was the presiding bishop of the First Council of Constantinople, and was later ordained a priest by Meletius's successor, who was probably Flavian. He was tasked with preaching, and it turned out that he was an impressive preacher. He developed his own style of preaching, which went successively through Scripture and looked at it step by step. His sermons when collected, therefore, made very close, very careful literal commentaries, and would on their own qualify Chrysostom to be considered one of the greatest theologians of his day.
In 397, however, he was suddenly and unexpectedly made Patriarch of Constantinople after the death of Patriarch Nectarius; he was a sort of dark horse, vaulted to the position for little reason other than the fact that he was a brilliant theologian who did not belong to any of the intensely opposed ecclesiastical factions that plagued Constantinople at the time. It was an interesting choice, because Chrysostom, unamused by the frivolity and finery of the capital, set out immediately to engage in an intensive reform of just about everything and to start preaching vehemently against the wealthy of the city. It took some time, but it was inevitable that something bad would happen to St. John; it was impossible to avoid politics in the capital, and Chrysostom, being a powerful preacher who was brilliant and spoke his mind, could hardly have avoided igniting an explosion at some point. At the instigation of the Empress, he was brought up before a synod on trumped-up charges, deposed, and exiled. However, his enemies hadn't quite reckoned on how much the poor of the city loved their Patriarch; they were on the verge of rioting before he was recalled from exile and reinstated. Tensions were still high, though; his enemies still looked for ways to depose him and at least two attempts were made on his life. Finally he was simply dragged out of church one day and sent into exile again. After he left the cathedral went up in flames, burning a large portion of the city with it; his supporters were accused of the arson and executed wherever they were found. Pope Innocent I protested his treatment, but was unable to do much. Chrysostom still had an extensive correspondence, which meant that his enemies couldn't be content even to leave him alone in exile; they captured him again and marched him off to an even more remote location, where he died along the way. His tomb is in Pitsunda, in the modern country of Georgia.