 Stephen IV's death transformed the conflict into a plain Byzantine–Hungarian war over Sirmium and Dalmatia; both areas were re-occupied by the Hungarians in 1166, after achieving major successes against the imperial forces.In response, Manuel I prepared a major counter-attack in 1167, appointing Andronikos, who months before had been named "megas doux", commander-in-chief of the Byzantine navy, as the leader of the campaign, although he also gave him detailed instructions for the campaign.The Hungarian army, commanded by the palatine Denis, met the Byzantine army near Zemun on the feast day of St. Procopius, 8 July 1167.