John Chrysostom was an influential archbishop of Constantinople during the early years of the Christian Church. He was born around 347 in Antioch, modern day Turkey. His preachings were so popular he was named golden mouthed. His explanations of the Bible were more literal instead of the allegorical interpretations that were common at the time.
John made a fast career in the early church, and was appointed archbishop of Constantinople. As the capitol of of the Eastern Roman Empire this was an important position. However, these early years of the Church were also very formative, and John appears not to have chosen the side of the winners of the arguments. It led to his banishment several times during his life. During one of these, his followers set fire to the old building of the Haga Sofia, built originally as a cathedral.
There is reason to assume he was also leading the opinion about Jews and homosexual men. In both his opinions would not pass current thinking. Some theologians have later seen his writings as one of the origins of catholic thinking about the subject.
John Chrystom was especially revered in the Eastern Orthodox Church, and as such his liturgy was put to music by several Russian composers, like Tchaikovsky and Rachmaninov. Estonian composer Arvo Pärt has written a litany with prayers for each hour of the day.
In 1204 his remains were stolen from Istanbul, during one of the Crusades. They were restored to their rightful place in Istanbul in 2004 by Pope John Paul II. There is some controversy about the location of his skull however. Some medieval discussions will never end.