The Question of Priestly Celibacy

This is a good overview of the origins of priestly celibacy. Especially interesting to me is that although advocates of a married priesthood always use the early Church as an example, in actuality they were expected to cease marital life upon achieving the priesthood.

Based on solid documentation, these authors show that although one cannot speak of celibacy in the strict sense of the word (not being married), it is certain that since apostolic times the Church had as a norm that men elevated to the deaconate, priesthood and the episcopate should observe continence. If candidates happened to be married - a very common occurrence in the early Church - they were supposed to cease, with the consent of their spouses, not only marital life but even cohabitation under the same roof...

Moreover, Church officials believed a person in those conditions would hardly have sufficient strength to halt marital relations and live under the same roof. Cardinal Stickler emphasizes that because of the mutually self-giving nature of matrimony; a separation would always take place only with the full consent the wife, who, for her part, would make a commitment to live in chastity in a community of women religious.

Via Being or Nothingness.