Born near Nancy, to a Frankish noble family in 582 AD, Arnulf gave distinguished service at the Austrasian court under Theudebert II (595-612). Though a capable man, he was also very much a man of the world, renouncing his wife Doda after a quarrel and becoming known for being “full lusty and ready for all delights." At the age of thirty, repenting of his sinful ways, he wished to retire to a monastery where he could make his peace with God. Instead, in 614, he was made bishop of Metz, despite a layman at the time. Even while serving as a model bishop, Arnulf, along with with Saint Pippin of Landen, served as chief adviser to kings Clotaire the Great and Dagobert I. In 627 AD Arnulf was finally allowed to retire to a mountain site in the Vosges, to implement his lifelong resolution to become a hermit. His friend Romaric had preceded him to the mountains and had already established the monastery of Remiremont there. Arnulf settled there, and remained there until his death twelve years later.
Arnulf is known as the patron saint of brewing. His feast day is either July 18 or August 16.