Pope Valentine

Pope Valentine (Latin: Valentinus; died 10 October 827) was the bishop of Rome and leader of the Papal States for two months in 827. He was unusually close to his predecessor, Eugene II, rumoured to be Valentine's father or lover, and became pope before being ordained as a priest. He was a nobleman and elected by nobility, which later became the custom.

Source: Wikipedia — https://en.wikipedia.org/wiki/Pope_Valentine