Catholics regard Peter as the first pope. In the gospel we learn that Peter's mother-in-law was healed, thus Peter was married. On the other hand, today the popes are never married and married men cannot be elected pope.

I'm interested in the chronology of this change from the first married to the unmarried, celibate popes of today.

1. Who was the last pope we know of was married?
2. From what point in time on can we know for sure no pope was married anymore?

Please note that between these two points in time there might be a substantial time span as a result of a lack of data or regulation.

Please also note that I am not interested in the history or the general merits of priestly celibacy as a whole, I was able to research that elsewhere.