 Father Maes served the diocese well, eventually rising to the position of chancellor of the diocese.During his time as a priest, Father Maes wrote a biography of Father Charles Nerinckx, one of the first Catholic missionaries in Kentucky and the founder of the Sisters of Loretto.Father Maes was named the third bishop of Covington by Pope Leo XIII on October 1, 1884, the first diocesan priest from Detroit to be named a bishop.