In 40 BC the Roman Senate confirmed Herod as King of Judea after intense lobbying by Mark Antony, a decision that would define Judean politics for the next generation. Herod's rule, propped up by Roman legions, would later see the massive expansion of the Second Temple and the deep resentments that shaped first-century Judea.
Herod fled to Rome after being driven from Judea by Parthian-backed rivals, arriving as a refugee with little but his connections to Mark Antony and, through him, Octavian. The Senate's vote made him king in name of a kingdom he did not yet control; he would need Roman legions to actually seize Jerusalem three years later.
The irony of Herod's kingship, granted by foreign decree rather than local acclaim or bloodline, haunted his reign and fed the suspicion of his subjects. His later building projects, the fortress of Masada, the harbor at Caesarea, the Temple itself, were partly attempts to legitimize a throne that always had a whiff of Roman puppetry about it.
Key people: Herod the Great, Mark Antony