St. Eusebius of Vercelli

St. Eusebius of Vercelli (283 - 1 August 371) was a bishop, and along with Athanasius, affirmed the divinity of Jesus against Arianism. He was the first bishop in the West to organize the clergy of his cathedral under a common rule of life, and so is counted as a remote founder of the Canons Regular. Eusebius worked with Hilary of Poitiers and Liberius, bishop of Rome, to restore Nicene doctrine in the churches of Italy.

See:
Writings of St. Eusebius

Catholic Encyclopedia article on Eusebius

Colonnade Statue in St. Peter's Square