The context of this second volume by Professor Duval is the trinitarian controversies of the later 4th century. His work presents a detailed analysis of the 'reconquest' of Northan Italy and Illyricum from the homeist dogmas put in place by Constans II and affirmed by the Council of Rimini in 359-60. Milan occupies a central place, first as a bastion of Arianism, then as the see of Ambrose, who eventually oversaw the victory of orthodoxy; as these studies show, the process was not straightforward, and even after the Council of Aquileia in 381, remained imperilled by the turbulent politics of the Empire. The final item, hitherto unpublished, gives a critical account of some recent work on Ambrose.