When decided priests cannot marry?

The decision that priests should not marry was formalized by the Roman Catholic Church during the Second Lateran Council in 1139, which prohibited the marriage of clergy. This practice was rooted in the belief that celibacy allowed priests to dedicate themselves fully to their spiritual duties and serve God without the distractions of family life. The tradition has been upheld over the centuries, although some Eastern Catholic and Orthodox churches allow married priests. The issue of clerical celibacy continues to be a topic of discussion and debate within the Church today.