Gunther of Pairis
Gunther of Pairis was a German Cistercian monk and author, writing in Latin.
His best-known work is his Historia Constantinopolitana about the Fourth Crusade, in a mixture of prose and verse. It was based on the account of Martin of Pairis, abbot of Pairis Abbey, and includes the siege and looting of Constantinople. His is the only western account to state explicitly that the crusaders pillaged Greek churches.
Gunther also wrote Solimarius, about the First Crusade, and Ligurinus, an epic about Frederick Barbarossa.