Saint Arsatius or Arsacius is a saint of whose life virtually nothing is known. He is said to have been a bishop of Milan, who lived either around 400 or in the 6th century, and possibly a martyr, but there is no evidence. Because of the traditional connection with Milan, he is further supposed to have been a disciple of Saint Ambrose, who was also Bishop of Milan, but there is no evidence of this either.Article about Arsatius and Ilmmünster on the Diocese of Munich website
His relics were brought in 766 from Rome to Ilmmünster Monastery where a cultus grew up around them and where the well-known Arsatius-Basilika is still dedicated to him. They were moved to Munich in 1495, but returned to Ilmmünster in 1846. His feast day is 12 November.
References
External links Saints.SQPN: Arsatius Site of Roman Catholic Archdiocese of Munich and Freising