This thesis examines the foreign policy of Constans II as the first Byzantine Emperor to rule after the initial Arab conquests in Syria-Palestine. His reign, 641-668, was the first reign of a Byzantine Emperor where the entire reign was subject to Arab raids and invasions. Constans II also had to contend with the Slavs in Thessalonica and Greece and the Lombards in Italy. To complicate matters more, Constans II was forced to cope with the religious division between the eastern and western churches due to Monothelitism in the East. Beset on every frontier and inheriting a much reduced empire after decades of intermittent warfare and several disastrous defeats, scholars have reasoned that Constans II's reign was defensive and turbulent in nature. This thesis uses literary and archeological sources to argue that Constans II had a foreign policy focused on actively retaking lost Byzantine territory. While stabilizing the frontiers in his early reign, he suffered devastating defeats and serious threats, primarily from the sea, where the Arab navy had gained superiority. His attempt in securing the western provinces of Italy and North Africa demonstrate not an emperor who was abandoning Constantinople, but one that was attempting to regain the initiative from the Arabs and deprive them of Egypt, which was providing the Arabs with a navy, wealth, and an agricultural surplus. Despite the Byzantine losses Constans II did not accept the transformation in Byzantine territory and influence. The thesis concludes with a historical analysis of his successors and how their foreign policies differed from Constans II's.