Ragusa (centered upon modern Dubrovnik), victimized by Dalmatian Muslim pirates, had joined Constantinople in 1030 in a series of naval wars against the raiders.

After their combined fleet crushes the pirates in the Adriatic in 1032, the imperial warships, manned chiefly by Scandinavian mercenaries, patrol the Mediterranean, winning several encounters over Muslim pirates and ravaging parts of North Africa's Muslim-controlled coast.