Valis,
(from a website)
"The celibacy of the priesthood was decreed by Pope Hildebrand, Boniface VII, in the year 1079 AD. Jesus imposed no such rule, nor did any of the apostles. On the contrary, St. Peter was a married man, and St. Paul says that bishops were to have wife and children. (Read 1st Tim. 3:2,5, and 12: Matt 8:14-15)."
An interesting historical timeline of Catholic theology and when it was mandated into their church is here:
http://members.tripod.com/~dabz_2/updates/heresy/heresy.html