He led a series of Balkan campaigns and managed to successfully re-establish the Danube as a northern border for his state (Limes Moesiae).

By Winter 602, his strategic goals included securing control of Pannonia and the area which would later be known as Wallachia.

When he decreed that the Byzantine army was to spend the winter of 602/603 on the northern bank of the Danube, the exhausted troops instead mutinied against their emperor.

He proclaimed chariot races in honor of his elevation and had Leontia escorted to the city as his new Empress.

According to the history of Theophylact Simocatta, the new imperial couple led a procession through the city as per custom.

The festive occasion was marked with renewed conflicts between the Blues and Greens, the two major chariot racing clubs.

The chariot racing factions honored the occasion by placing images of Phocas, Leontia, Domentzia, and Priscus in the Hippodrome of Constantinople.