He was a celebrated "fee-less physician" from Nicomedia who placed his skill in the service of God's kingdom! According to legend he was the emperor's ordinary physician. He is said to have strayed from the faith because of the voluptuous life at the court, but the zealous priest Hermolaus, by pointing out the example of his virtuous mother, effected such a change that Pantaleon distributed his goods among the poor and devoted his talents for healing to the most wretched and poor among the sick.

Because of his Christian faith he was seized by order of Emperor Maximian, tied to the rack and scorched with torches. But in these tortures Christ appeared, granting him further strength. Finally a stroke of the sword ended his sufferings (Martyrology). He is the patron of physicians and belongs to the "Fourteen Holy Helpers."

http://www.catholicculture.org/culture/liturgicalyear/calendar/day.cfm?date=2013-07-27