The Archdiocese of San Francisco (Latin: Archdiœcesis Sancti Francisci; Spanish: Archidiócesis de San Francisco) is a Latin Church ecclesiastical territory or diocese of the Catholic Church in the northern California region of the United States. It covers the City and County of San Francisco and the Counties of Marin and San Mateo. The Archdiocese of San Francisco was canonically erected on July 29, 1853, by Pope Pius IX and its cathedral is the Cathedral of Saint Mary of the Assumption.