James was a member of a noble Polish family. He entered the Franciscan friars at an early age, serving as guardian at a friary in Lvov and alleviating tensions between the friars and the local diocesan clergy. He showed special interest in working with the Orthodox, ministering among them for a full decade. Sent to western Russia, he served as vicar general of the Franciscans there, preached the gospel and worked to sustain the faithful in their beliefs.
Around 1360, he played a role in the organization of a special group of Franciscan missionaries, Travelers for Christ, made up of Franciscan and Dominican friars. James's work as a missionary preacher and organizer was decidedly successful. In due time he was appointed Archbishop of Galich, and took it upon himself to build new churches in remote districts and to staff them with experienced priests from Poland; he also founded and built religious houses, schools and hospitals. He had such a flair for the practical needs of his people that he often took his suggestions directly to the Polish parliament; such actions earned him the title of "protector of the kingdom."
He was an archbishop unlike many in his day, preferring to wear a simple Franciscan habit rather than ostentatious attire and to travel on foot.
He was especially devoted to the Blessed Mother. Her image was engraved on his seal and was on his pastoral ring. Each evening devotions were held in her honor at the cathedral or wherever he was visiting.
After serving 19 years as bishop, James was called to his eternal reward. He is buried in the Franciscan Church at Lvov.