Some do seem to bear family relationships, falling into two main branches, the Ottaviani and the Stefaniani, and their policies were consistent enough, especially as regards confronting the rival gang of aristocratic thugs, the Tusculani, who were descended from the influential curial official Theophylact, Count of Tusculum, ruler of Rome at the beginning of the 10th century.

The Crescentii had another formidable enemy, whose power did not always extend to Rome, in the German kings and emperors of the Ottonian Saxon dynasty, notably Otto the Great and Henry II.

They held the secular offices such as praefectus by which Rome was technically still governed, and exacted large contributions and donations from the Papal treasury, in a thinly disguised extortion.

After Sergius IV's death (1012), the Crescentii simply installed their candidate, Gregory, in the Lateran, without the assent of the cardinals.

The failure of their bold attempt and the pontificate of the Tusculan pope Benedict VIII, whose powerful protector was the King of the Germans, Henry II, whom he crowned Emperor in Rome in 1014, forced the Crescentii out of Rome, retreating to the fortified strongholds.