The Monk Greasim was born in the city of Chalkida, on the island of Euboea, into a noble Frankish or Italian family. According to the author of the Life, St. Callista I, Gerasim belonged to the royal family of Fatsos, which, apparently, means the family of Boniface of Montferrat († 1207), king of Thessalonica, or, according to researcher P. A. Sirku, the family of one of the Euboean barons, Boniface della Carceri († 1317), who came from Verona. Leaving wealth and fame, Gerasim retired to Sinai, where St. Petersburg became his mentor. Gregory Sinait. In the Life of St. Gregory of Sinaita Gerasim is named the first disciple of the famous hesychast. Together with him, he subsequently went to Greece and labored on the Holy Mountain.
Patriarch Callistus I writes about the virtues and ascetic exploits of Gerasim of Euboea, who imitated St. Gerasim of Jordan. The saint gathered a monastic community and organized several hesychastries. The monks who lived in them practiced silence and smart work.
The future Patriarch of Constantinople Isidore I (1347-1350) was also a student of Gerasim of Euboea.
St. Gregory the Serb, Silent, Athonite, ktitor († after 1405, commemorated December 7)