However, around 1319, the city was invaded by the Catalan troops of Alfonso Fadrique of Aragon and fell into the hands of the Duchy of Athens.

[5] Athanasius left Mount Athos with two other monks and went in search of an isolated place to practice asceticism.

After several attempts, a disciple of Gregory of Sinai, who had become a bishop, advised them to go to Thessaly, in the region of Meteora, where hermits had already been living since the 11th century.

[6] Athanasius saw that the peaks of Meteora were ideal for monasticism, and they decided to settle on the top of a rock where a rock-carved chapel had already existed.

[5] Athanasius therefore left for the highest rock, called the "Meteor," and accepted with him only those monks who were most capable of leading a very austere life.

In 1356,[7] he organized the community by giving it a cenobitic monastic rule, following the Typikon of the monasteries of Mount Athos.

[8] The foundation of the monastic community was protected and sponsored by the local lord Simeon Uroš, based in nearby Trikala, who that same year proclaimed himself Emperor of Serbs and Greeks following the death of Stefan Dušan.

It was also said that Athanasius had acquired the gift of prophecy and predicted the failed siege of Thessalonika by the Ottomans in 1372.