Herod had the throne, but the Hasmonean family still haunted him. His wife Mariamne was a Hasmonean princess. Her mother Alexandra was relentless in promoting Hasmonean claims. And the most dangerous threat of all was a seventeen-year-old boy named Aristobulus III, Mariamne's younger brother, the last male Hasmonean who could legitimately serve as high priest.
Herod initially tried to sideline the boy by appointing an obscure priest from Babylon to the high priesthood. Alexandra was furious. She secretly wrote to Cleopatra, queen of Egypt, who pressured Mark Antony to intervene. Herod, sensing danger from Antony's involvement, reversed course and appointed young Aristobulus as high priest.
It was a catastrophic miscalculation. Josephus describes in his <i>Antiquities</i> what happened next. During the Festival of Sukkot, the teenage Aristobulus stood at the altar in his priestly vestments. The crowds went wild. They wept. They shouted blessings. They showered the boy with the kind of adoration that made very clear where their loyalties lay. Herod watched it all and understood that this boy would destroy him if he lived.
Shortly after the festival, Herod invited Aristobulus to a banquet at his palace in Jericho. It was a warm evening. After dinner, the party moved to the pools in the courtyard. The young men began swimming and playing in the water. As night fell, some of Herod's men pushed Aristobulus under the surface and held him down. They kept dunking him, as if in sport, until he drowned.
He was eighteen years old.
Herod staged an elaborate funeral, weeping publicly, playing the grieving brother-in-law. Nobody was fooled. Alexandra reported the murder to Cleopatra, who again pressured Antony. Herod was summoned to explain himself. He went to Antony loaded with gifts and bribes. Before leaving, he gave secret orders to his deputy Joseph: if Herod did not return alive, Joseph was to kill Mariamne immediately. Herod could not bear the thought of his wife surviving him and belonging to another man.
Antony acquitted him. The bribery worked. But the secret order about Mariamne would soon leak out, setting in motion a chain of jealousy and murder that would consume Herod's entire household.