Follis - Valentinianus I RESTITVTOR REIP, Sirmium

Valentinian I took power in February 364 AD, and within months had divided the empire with his brother Valens — Valentinian holding the West, Valens the East. Sirmium, seated on the Sava River in modern Serbia, served as one of his primary western residences and a key military staging point against Quadi and Sarmatian incursions across the Danube frontier. The RESTITVTOR REIP type was not decorative flattery; Valentinian was actively rebuilding collapsed border fortifications along the Rhine and Danube simultaneously, a logistical effort documented in Ammianus Marcellinus.

RIC IX 6a places this emission in the first officina at Sirmium, datable by the mintmark sequence to the early years of the reign before the pressure of the 367 Alamannic crossing forced a shift in imperial priorities.