One theory for the institution of priestly celibacy was that the early Church experienced a problem with priests handing over Church property two their sons thus fostering a culture nepotism within the Church. I also read that the first 40 or so Popes were married as well. And that the institution of celibacy was formally implemented by the Council of Trent to correct the abuses. In other words, celibacy was used to combat nepotism, abuse, and scandal.
Can you post some linked references? Thank you!