Roman Catholic Diocese of Helena Roman Catholic Diocese of Helena The Diocese of Helena () is the Catholic diocese for western Montana with its cathedral located in Helena, the state capital. The diocese was erected from the year-old Vicarate of Montana on March 7, 1884, while Montana was still a territory. The diocese is a suffragan of the Archdiocese of Portland, which encompasses Oregon, Idaho, and Montana. Before becoming a diocese, this was the Vicariate of Montana (covering the whole territory and then state of Montana). For its first twenty years, the diocese served all of Montana. In 1904 the new Diocese of Great Falls-Billings
Coat of arms of Saint Helena shows the flag of England flying from the ship (when the shield was first introduced in 1874 the flag was a White Ensign). The motto is "Loyal and unshakable". The full coat of arms features, above the shield, a woman holding a cross and a flower. This represents Helena of Constantinople, also known as Saint Helena, after whom the island is named. The cross is shown as Helena is credited with finding the relics of the True Cross (cross upon which Jesus was crucified). The shield of the arms features on the flag of Saint Helena and the Governor's flag.