After the peace treaty with the Persians and subsequent Roman refocusing on the Balkans as mentioned above, Maurice deployed veteran troops to the Balkans, allowing the Byzantines to shift from a reactive strategy to a pre-emptive one. The general Priscus was tasked with stopping the Slavs from crossing the Danube in spring 593. He routed several raiding parties, before he crossed the Danube and fought the Slavs in what is now Wallachia until autumn. Maurice ordered him to make camp on the northern bank of the Danube, however Priscus instead retired to Odessos. Priscus' retreat allowed for a new Slav incursion in late 593/594 in Moesia and Macedonia, with the towns of Aquis, Scupi and Zaldapa being destroyed.

In 594 Maurice replaced Priscus with his own brother, Peter. Due to his inexperience, Peter suffered initial failures, but eventually managed to repulse the tide of Slav and Avar incursions. He set up base at Marcianopolis, and patrolled the Danube between Novae and the Black Sea. In late August of 594, he crossed the Danube near Securisca and fought his way to the Helibacia river, preventing the Slavs and Avars from preparing new pillaging campaigns. Priscus, who had been given command of another army, prevented the Avars from besieging Singidunum in 595, in combination with the Byzantine Danube fleet. After this, the Avars shifted their focus to Dalmatia, where they sacked several fortresses, and avoided confronting Priscus directly. Priscus was not particularly concerned about the Avar incursion, as Dalmatia was a remote and poor province; he sent only a small force to check their invasion, keeping the main body of his forces near the Danube. The small force was able to hamper the Avar advance, and even recovered a part of the loot taken by the Avars, better than expected.