Crescentius
The head of the Nationalist party, which pushed Franco as their candidate for the papacy when Otto the Great was still in power, was the powerful Crescentii family. The family arose from the aristocracy in the 10th century and began to take on a major role in politics in the 970s after the death of Pope John XIII who had family ties with Crescentius. However, when Otto the Great designated Benedict VI as the next pope, the Crescentii family, along with most of the Roman people, began to feel indignation towards the emperor because they felt he was interfering too much in the papal elections. When Otto the Great died and Otto II took over, Crescentius led the rebellion against the imperial regime which would eventually lead to the installment of Franco to the papacy.
Read more about this topic: Antipope Boniface VII