During the following years he had leisure to carry out those splendid works of peace by which it was his aim to ingratiate himself with the emperor.  He founded cities and harbours (Antipatris, Caesarea), constructed roads, theatres, and temples, and subsidised far beyond his frontier all works of public utility.  He taxed the Jews heavily, but in compensation promoted their material interests with energy and discretion, and built for them, from 20 or 19 B.C. onwards, the temple at Jerusalem.  To gain their sympathies he well knew to be impossible.  Apart from the Roman legions at his back his authority had its main support in his fortresses and in his system of espionage.

But just as the acme of his splendour had been reached, he himself became the instrument of a terrible vengeance for the crimes by which his previous years had been stained; as executioner of all the Hasmonaeans, he was now constrained to be the executioner of his own children also.  His suspicious temper had been aroused against his now grown-up sons by Mariamne, whose claims through their mother to the throne were superior to his own; his brother Pheroras and his sister Salome made it their special business to fan his jealousy into flame.  To show the two somewhat arrogant youths that the succession was not so absolutely secure in their favour as they were supposing, the father summoned to his court Antipater, the exiled son of a former marriage.  Antipater, under the mask of friendship, immediately began to carry on infamous intrigues against his half brothers, in which Pheroras and Salome unconsciously played into his hands.  For years he persevered alike in favouring and unfavouring circumstances with his part, until at last, by the machinations of a Lacedemonian, Eurycles, who had been bribed, Herod was induced to condemn the sons of Mariamne at Berytus, and cause them to be strangled (Samaria, 7-6 B.C.).  Not long afterwards a difference between Antipater and Salome led to the exposure of the former.  Herod was compelled to drain the cup to the dregs; he was not spared the knowledge that he had murdered his children without a cause.  His remorse threw him into a serious illness, in which his strong constitution wrestled long with death.  While he lay at Jericho near his end he gave orders for the execution of Antipater also; and to embitter the joy of the Jews at his removal he caused their elders to be shut up together in the hippodrome at Jericho with the injunction to butcher them as soon as he breathed his last, that so there might be sorrow throughout the land.  The latter order, however, was not carried out.