The challenge for Peter the Venerable was to establish a theological and historical nexus between Muhammad and the Nicolaitan heresy.
Nicolas had also founded the Nicolaitan sect, which in the long trajectory of its history became associated exclusively with sexual immorality.
Muhammad, as a latter day Nicolaitan, represented an apostate who once had the opportunity to know the truth, but chose rather to follow his unbridled pride into doctrinal error and sexual immorality.
To do so, moreover, these polemicists harkened back to the patristic era to revive the Nicolaitan heresy to condemn medieval clerical marriage.
Ulrich D'Insola, on the other side of the debate, rejected the epitaph of Nicolaitan to argue that secular clergy should be allowed to marry.
For an early Christian usage of the Nicolaitan type see, A.
Irenaeus linked Nicolas, one of the alleged seven deacons consecrated at Jerusalem by the Apostles, with the sect of Nicolaitans that was flourishing in the second century.
In the fourth and fifth centuries a sect of Nicolaitans no longer existed, but a topos of Nicolaitism surfaced and remained deeply ingrained in the heresiological literature.
Peter instead believed the immorality of the sect of the Nicolaitans had been made manifest again in the practices [legem] of the contemporary Saracens [modernorum Sarracenorum].
The narrative, while completely setting aside the patristic tradition of Nicolas as a successor of Simon Magus, succeeded through Maurus in providing the much needed mediator between the Nicolaitans and Muhammad.
The Nicolaitans have received more extensive commentary in modern scholarship.