Eufranio Desiderio entered the Capuchins at Spoleto at eighteen in 1574, was ordained priest in 1580, and worked for fifteen years as a wandering preacher in the Marche and Umbria. In 1587, then thirty-one, he was sent at his own request to the Capuchin mission at Constantinople, where the order ministered chiefly to the substantial Christian slave population of the Ottoman capital (an estimated thirty to fifty thousand European Christians held as slaves in Constantinople during the late 16th century).
He spent six years (1587–93) at the Constantinople mission. He worked openly in the slave compounds, secretly evangelized among Turks (a capital offence), and twice attempted to preach in the Sultan's own court at the Topkapi Palace — for which he was arrested, tortured (hung by chains piercing his hand and foot for three days), and finally released into exile to Italy when his Italian protector, a converted Turkish doctor, intervened. The wounds in his hands remained open and bleeding for the rest of his life.
He returned to the Italian missions until his death from cancer at Amatrice in 1612. Canonized 1745.