On the site of the old tower of the monastery, built by Ivan Assen II, and burnt down on October 10th 1275 a monument was raised in 1873 in memory of the 26 Zograph martyrs who died in the fire. Owing to the resolute refusal to on the part of the community of monks at Zograph to abandon Orthodoxy, by accepting the Union between the Western and Eastern church, pronounced at the First Church Council at Lyon (1245), on October 10th 1275 the monastery was attacked by crusaders (Catalan mercenaries) who destroyed the monastery and burnt the 22 monks and 4 laymen brothers alive.