St. John Chrysostom lived from about the second half of the fifth and just into the sixth century (347-407). He was the Archbishop of Constantinople and is a Doctor of the Catholic Church.
Tyler Marshall over at Canterbury Tales has a very intersting post on St. John Chrysostom's denouncing the "evil filth" of contraception:
Contraception; something worse than murder. It appears that Humanae Vitae wasn't the first time the topic was addressed in the Church.
"Why do you sow where the field is eager to destroy the fruit, where there are medicines of sterility [oral contraceptives], where there is murder before birth? You do not even let a harlot remain only a harlot, but you make her a murderess as well…Indeed, it is something worse than murder, and I do not know what to call it; for she does not kill what is formed but prevents its formation. What then? Do you condemn the gift of God and fight with his [natural] laws?…Yet such turpitude…the matter still seems indifferent to many men—even to many men having wives. In this indifference of the married men there is greater evil filth; for then poisons are prepared, not against the womb of a prostitute, but against your injured wife. Against her are these innumerable tricks."
- St. John Chrysostom Homilies on Romans, 24 (ca. A.D. 391).