Herod was no stranger to political ruthlessness. He lived a very dog-eat-dog life. With reports of the birth of the "king of the Jews" (Matthew 2:2) it was entirely natural for his way of thinking to seek to kill the potential rival, including many other innocents in the effort: "he sent and killed all the male children in Bethlehem and in all that region who were two years old or under, according to the time which he had ascertained from the wise men" (Matthew 2:16 RSV). He is also believed to have killed some of his own children from time to time, and at least one of his numerous wives. Put most simply, the man was a brute.
Some are surprised when they first learn that Herod had Jewish connections. His family was of Idumaean origin, those who had been converted to Judaism by force by the Hasmonean king John Hyrcanus. He was an observant Jew (perhaps the primary reason for his fear and fury when he heard of the birth of the "king of the Jews" in Bethlehem), involving himself in a complete reconstruction of the Temple and Temple Mount. This did not endear him to the Jews of Jerusalem however. He was very much disliked by them because they were all too well aware that his true loyalty was to his Roman political masters (see Ancient Empires - Rome).
Herod was assigned a territorial rulership by the Romans, making him a "client king." His area covered from Gaza to Masada in southern Israel, north beyond Nazareth, and then a section east beyond the Golan Heights into what is today Syria. If Herod had not died while Jesus was still an infant, he certainly would have been a problem later because this is the very area that Christ lived and conducted His entire recorded ministry.
Like many despots who had vast sums of public money available, Herod considered himself a great builder. In fact, he is responsible for a number of great construction projects, including the Herodian Temple (see Temples), the peculiar Herodium, and the Fortress Of Masada (in photo above) out near the Dead Sea.
The Herodian Temple was a tremendous expansion of the Temple Mount from the more humble results produced by the returning Jews during the time of Ezra and Nehemiah. It was Herod's great reconstructed Temple that Jesus Christ walked about in during His lifetime, and where the well-known incident of driving out the money changers occurred, when Jesus called it "My Father's House" (John 2:14-16). Jesus also prophesied its eventual destruction, which occurred in 70 A.D., "And as some spoke of the Temple, how it was adorned with noble stones and offerings, He said, "As for these things which you see, the days will come when there shall not be left here one stone upon another that will not be thrown down." (Luke 21:5-6 RSV) (see Fall of Jerusalem In 70 A.D.)
Herod is believed to have died at his Winter Palace in Jericho around 4 B.C., not very long (perhaps not more than a year) after Joseph and Mary fled with Jesus into Egypt. "But when Herod died, behold, an angel of the Lord appeared in a dream to Joseph in Egypt, saying, "Rise, take the child and his mother, and go to the land of Israel, for those who sought the child's life are dead." And he rose and took the child and his mother, and went to the land of Israel." (Matthew 2:19-21 RSV).
Fact Finder: Who did Herod ask to find the Christ child for him?
(a) the Pharisees (b) the Magi ("wise men") (c) the Roman army