St. Ambrose (De Officiis, I, 1): Some married clergy existed in close of 4th Century (in outskirts of Rome/Milan)

Source: http://www.newadvent.org/cathen/03481a.htm (21 Jan. 2020)

Excerpt: Although it is true that at the close of the fourth century, as we may learn from St. Ambrose (De Officiis, I, l), some married clergy were still to be found, especially in the outlying country districts...