(in English, St. Ambrose). Born circa 340; died Apr. 4, 397. Bishop of Milan (Mediolanum) from 374. Preacher, theologian (recognized as a father of the church by the Catholic Church), and church politician.
From 370 to 374, Ambrosius was vicegerent of Liguria and Emilia (with residence in Milan). Upon becoming bishop, Ambrosius defended the interests of the Christian church in a series of conflicts with imperial power. His most important work, Duties of Clerics (Russian translation, 1908), sets forth a system of Christian ethics. He fought against paganism and Arianism. He composed church hymns and established the principles of ritual singing in the western Christian church (the so-called Ambrosian hymns).