Dante Alighieri and Francesco took part in this campaign. During the Crusades, a fraudulent Bishop promised the Crusaders absolvement for their sins in payment for taking the fight up. They waged war with Saladin's Muslim forces and eventually captured the city of Acre. Dante committed numerous sins during this "Holy" war and was damned as a result. The King held the innocent prisoners in an attempt to negotiate the return of the True Cross. Before the negotiations could be fleshed out, (If they ever would be) Dante initiated the slaughter at Acre in a fit of rage. Following this, King Richard demanded the one who was responsible to step forward. Francesco took the fall for his brother and was sentenced to be hanged.
The Siege of Acre
In reaction to the atrocities that are committed, Saladin assaulted Acre and a riot ensued. The prisoners escaped and Dante continued to slaughter them with his Halberd though one Kurdish prisoner managed to stab him in the back. Death appeared and prepared to damn him to Hell for his sins. He refused to accept his fate and defeated the reaper by taking his Scythe.
In the Inferno, Dante encountered his former brothers in the circle of Violence in the Abominable Sands for their deeds "Done in the name of God." Here, he encountered Francesco who confronted him for his sins.