Commemorated on July 27
The Great Martyr and Healer Panteleimon was born in the city of Nicomedia into the family of the illustrious pagan Eustorgius, and he was named Pantoleon. His mother Saint Euboula (March 30) was a Christian. She wanted to raise her son in the Christian Faith, but she died
when the future martyr was just a young child. His father sent Pantoleon to a pagan school, after which the young man studied medicine at Nicomedia under the renowned physician Euphrosynus. Pantoleon came to the attention of the emperor Maximian (284-305), who wished to appoint him as royal physician when he finished his schooling.
For more;
https://www.oca.org/saints/lives/2020/07/27/102099-greatmartyr-and-healer-panteleimon