Pope Gregory VII attempted to mandate
When was celibacy instituted in the Catholic Church?
The universal requirement to celibacy was imposed upon the clergy with force in 1123 and again in 1139.
Why did celibacy begin in the Catholic Church?
The Vatican regards it as being easier for unattached men to commit to the church, as they have more time for devotion and fewer distractions. The earliest written reference to celibacy comes from 305AD at the Spanish Council of Elvira, a local assembly of clergymen who met to discuss matters pertaining to the church.