Matthew Bonnellus (Italian: Matteo Bonello or Bonnel) was a rich knight of an ancient and influential Norman family who became the lord of Caccamo in Sicily.
According to Hugo Falcandus, on 10 November 1160, rumours began circulating in Palermo that "the King was coming that night, at Maio's instigation, to the Archbishop's palace, and that there, in that very street, he was to be slain."
Bonnellus himself fled to Caccamo, but his popularity in the streets of the capital was such that the king was forced to grant him a pardon and he reentered Palermo as a hero.
Under the urging of Queen Margaret, however, the king was prompted to demand a long-overlooked duty, a payment owed by Bonnellus for his inheritance, of 60,000 taris.
Reinforcements arrived from Messina and the rebels were forced to accept very generous terms: exile for all and pardon for Bonnellus himself.