After the collapse of the Bulgaria in 1018, Duklja became a vassal of the Byzantine Empire, but soon after the death of emperor Romanos III Argyros in 1034, Stefan Vojislav rebelled against the Byzantines. However, the rebellion was extinguished in 1036 and Stefan Vojislav was captured and taken to Constantinople. The direct Byzantine rule in Serbia was restored and the new "strategos" of Serbia was general Theophilos Erotikos. Stefan Vojislav escaped from his captivity in 1037 or 1038, returned to Serbia by 1039, expelled Theophilos and then expanded the territory under his rule capturing Duklja and the "Illyiran Coast" (cities of Bar, Ulcinj and Scutari), which belonged to the Byzantine Theme of Dyrrhachium. He also began to attack and plunder the imperial ships on the Adriatic in the winter of 1039–1040. This prompted the next emperor, Michael IV the Paphlagonian (ruled 1034-1041), to send an expedition against Stefan Vojislav in the spring of 1040, under the command of eunuch Georgios Provatas. Provatas was heavily defeated: "arriving in the country and entering deep into the gorges, ravines and trackless lands, he lost his entire army, barely saving himself".