There were individuals pushing for compulsory clerical celibacy from the beginning. But it was not institutionalized until the Middle Ages. I refer you to Canon 21 instituted at the First Lateran Council in 1123. “We absolutely forbid priests, deacons, subdeacons, and monks to have concubines or to contract marriage.” Of course this canon has since been changed so that deacons are now permitted to be married.
There have been many Church leaders throughout the ages who have clamored for compulsory clerical celibacy. Many of these individuals quite frankly had issues with intimacy-—even that between a husband and a wife-—and some had issues with women. The Orthodox Church in the East would have none of it, and you finally had the Great Schism between the Western (Latin Rite) Church and the Eastern (Orthodox) Church. To this day Orthodox priests are permitted to be married and they have always been permitted to be married. There are even Catholic Churches in Eastern Europe and the Middle East which permit married men to be ordained as priests.
Some early Church leaders had such issues with physical intimacy that they even developed the dogma that Mary herself was always a virgin, even though the Bible only states that Mary was a virgin at the time of her conception of Jesus and goes no further than that and there is the fact that Mary had a husband and Jesus had brothers and sisters specifically mentioned in the Bible. Some of these early Church leaders seemed to think that Mary would have somehow been defiled even by engaging in physical intimacy with her own beloved spouse. A silly idea when you think about it. The Lord commands us to be fruitful and multiply and Mary and Joseph did just that. Sex is not a dirty thing. Holy Matrimony and physical intimacy between husband and wife is God’s plan and is something that would not have been denied to Mary and Joseph and certainly not denied to our priests. There is no requirement for such a draconian policy in the Bible.
-— even though the Bible only states that Mary was a virgin at the time of her conception of Jesus and goes no further than that and there is the fact that Mary had a husband and Jesus had brothers and sisters -—
Mary is ENGAGED to Joseph when Gabriel tells her, “You will bear a child...”
Mary doesn’t reply, “well, I AM getting married, after all.”
No. She asks, “How can this be?”
Interpret this as you like. Luther has given you permission. But Sacred Tradition interprets this as reflecting Mary’s vow of perpetual virginity. I will go with the Teaching of Christ’s Church, “the pillar and foundation of truth.”
“If he will not listen to the church, treat him as a pagan or tax collector.” —Jesus
The word for “brothers and sisters” can also mean cousins.
Jesus and Paul COMMEND celibacy IN THE BIBLE, if that carries any weight with you.
Which was not an innovation, but a reiteration of what was already required. Canon 33 of the Synod of Elvira said much the same thing.
It didn't "develop"; it was always what was believed, and is the only possibility that is consistent with Mary's words to the angel, and Jesus' giving Mary to John on Calvary.