Originally Posted by Wikipedia

Celibacy for priests is a discipline in the Roman Catholic Church, not a doctrine: in other words, a church regulation, but not an integral part of Church teaching. It is based upon the life of Christ and his celibate way of life. However the first pope, St. Peter, as well as many subsequent popes, bishops, and priests during the church's first 270 years were in fact married men, and often fathers. The practice of clerical continence along with a prohibition of marriage to men once ordained a deacon, priest or bishop by the Council of Elvira. This law was reinforced in the West at the Council of Carthage in 390. It remains law today for Latin Rite Catholics, but not for Eastern Catholics. Until recently, the Eastern Catholic bishops of North America would generally ordain only unmarried men, for fear that married priests would create scandal. Since Vatican II's call for the restoration of Eastern Catholic traditions, a number of bishops have returned to the traditional practice of ordaining married men to the presbyterate. Bishops are still celibate and normally chosen from the ranks of monks.