After the defeat, Harald and the Varangian Guard were called back to Constantinople, following Maniakes' imprisonment by the emperor and the onset of other more pressing issues. Harald and the Varangians were thereafter sent to fight in the southeastern European frontier as the Balkan peninsula in Bulgaria, where they arrived in late 1041. There, he fought in the army of Emperor Michael IV in the Battle of Ostrovo of the 1041 campaign against the Bulgarian uprising led by Peter Delyan, which later gained Harald the nickname the "Bulgar-burner" (Bolgara brennir) by his skald.