Francesco Bussone, also known as the "Carmagnola" was the captain-general of the Most Serene Republic of Venice. He was found guilty of treason and collusion with the enemy (Filippo Maria Visconti) and beheaded in 1432. The accusation was unjust but his head was to remain on display to the people as was customary, giving rise to a legend that would long be remembered in the popular imagination. The head, made of red porphyry, is located in the loggia of the Basilica and always seems to serve as a warning to the visitor. It comes from the plundering of Constantinople carried out during the Fourth Crusade of 1204. It has long been a focal point in studies and discussions to determine the historical identity of the character represented. Discounting the identification with a sovereign of the late Empire it is probably, on the basis of comparison of coins, a depiction of Justinian I.