In 1275, the Monastery, renovated by Ivan Asen, was attacked by the Latins, who came to force the monks of Mount Athos to accept the Union of Lyon (1274), signed by Emperor Michael VIII Palaeologus, and to accept the supremacy of the Pope of Rome. The Zograf monks held fast to the doctrines of the Orthodoxy and opposed the Union. Twenty-two of the most steadfast monks and four laymen remained within the Monastery tower and were burnt alive by the Latins for their Orthodox Faith on 10 October 1275.
Soon after, the holy Monastery was restored and strengthened, enjoying the generous support of the Byzantine emperors and the Bulgarian kings. Already in 1289, the Byzantine Emperor Andronicus II Paleologos confirmed all the old rights and possessions of the Monastery with a golden bull. In 1342, Tsar Ivan Alexander donated to Zograf many properties through which the Monastery was supplied with the necessities of earthly life. At the end of the 14th century, the connections and literary contacts with the Bulgarian lands and especially with the capital city of Tarnovo increased. At that time, two Bulgarian saints, Theodosius of Tarnovo and Euthymius, the future Patriarch of Tarnovo, lived on Mount Athos.
Compiled by: Georgi Mitov