Herod was granted the title of "King of Judea" by the Roman Senate. As such, he was a vassal of the Roman Empire, expected to support the interests of his Roman patrons. Nonetheless, just when Herod obtained leadership in Judea, his rule faced two threats. The first threat came from his mother-in-law Alexandra, who sought to regain power for her family, the Hasmoneans, whose dynasty Herod had overthrown in 37 BCE (see Siege of Jerusalem). In the same year, Cleopatra married the Roman leader Antony. Recognizing Cleopatra's influence over Antony, Alexandra asked Cleopatra for aid in making Aristobulus III the High Priest. As a member of the Hasmonean family, Aristobulus III might partially repair the fortunes of the Hasmoneans if made High Priest. Alexandra's request was made, but Cleopatra urged Alexandra to leave Judea with Aristobulus III and visit Antony. Herod received word of this plot, and feared that if Antony met Aristobolus III in person he might name Aristobulus III King of Judea. This concern induced Herod, in 35 BCE, to order the assassination of Aristobulus, ending this first threat to Herod's throne. The marriage of 37 BCE also sparked a power struggle between Roman leaders Octavian, who would later be called Augustus, and Antony. Herod, owing his throne to Rome, had to pick a side, and he chose Antony. In 31 at Actium, Antony lost to Octavian, posing a second threat to Herod's rule. Herod had to regain Octavian's support if he was to keep his throne. At Rhodes in 31 BCE, Herod, through his ability to keep Judea open to Rome as a link to the wealth of Syria and Egypt, and ability to defend the frontier, convinced Octavian that he would be loyal to him. Herod continued to rule his subjects as he saw fit. Despite the autonomy afforded to Herod in his internal reign over Judea, restrictions were placed upon him in his relations with other kingdoms.