After a few years in Kievan Rus', Harald and his force of around 500 men moved on south to Constantinople (Miklagard), the capital of the Eastern Roman Empire where they joined the Varangian Guard. While the Varangian Guard was primarily meant to function as the emperor's bodyguard, Harald was found fighting on "nearly every frontier" of the empire. He first saw action in campaigns against Arab pirates in the Mediterranean Sea, and then in inland towns in Asia Minor / Anatolia that had supported the pirates. By this time, he had according to Snorri Sturluson become the "leader over all the Varangians".