Once, long ago, the Roman people had been freed from the emperors by the Popes. But after the Popes took charge of the government, the Roman people rebelled against them too. While the Popes caused other nations to tremble in fear, the people of Rome were in open rebellion against the papal power.
Bruno of Carinthia became Pope Gregory V in 996 Anno Domini. It was he, according to Niccolo Machiavelli, who deprived the Romans of their share in the election of Popes. Henceforth, it would be the Cardinals alone who would decide. It was a new, technocratic way of governing.
After the death of Pope Gregory V, according to Machiavelli, there was a schism in the church. Gregory V had died suddenly, in 999 Anno Domini, and not without suspicion of foul play. The new Pope, Sylvester II (nee Gerbert d’Aurillac), either himself built a bronze head, or acquired same from the Buddhist secret society of the Nine Unknown Men, which bronze head could answer questions with either a “yes” or a “no.” (Further details in my book, Melchizedek Communique, published by Lulu.com)
By the time Anselmo da Baggio became Pope Alexander II, in 1061 Anno Domini, the “schism” had widened into an open dispute with Germany. The imperial court of Germany chose Cadalus of Parma to be an alternate Pope! This alternate Pope, Honorius II, is since called an “Antipope.” But who exactly was the real Antipope, Alexander II or Honorius II? Will the real Antipope please stand up!? The difficulty of two Popes at the same time was finally resolved by actual warfare between the armies of the two papal claimants. Honorius II eventually lost the battle, and so he became the Antipope. (Had the battle gone differently, Alexander II would be called the Antipope.)
At any rate, while the two papal pretenders battled it out, some of the Italians sided with Alexander II, but others sided with Honorius II. And hence arose the factions of the Guelphs and the Ghibellines.
(Acknowledgement to History of Florence, by Niccolo Machiavelli)