Although Herod was the 'King of the Jews', he wasn't actually a Jew! He was a Nabatean and was really a 'puppet king' for the Romans. Herod was hated by most Jews and he didn't like them either! So when the Magi said there was a new 'King of the Jews' - who was actually Jewish - was very angry and was scared the new King could come and take his power away.
Because Herod was unable to find out where Jesus was from the wise men, he thought the only way of making sure Jesus was killed was to kill every baby boy under two years old in Bethlehem and the surrounding area. Probably only about 20 babies would have been killed, but even that fact is really horrible. So his cruelty would have brought terror and grief to many homes. But Jesus was kept safe as Joseph took him and Mary to Egypt just in time. This was not the first time that Herod had killed people to keep them quiet - he even had killed people in his own family in the past!
The killing of the boys is mentioned in a Roman book in the 5th century, called "The Saturnalia of Macrobius" where it also claims that even one of Herod's sons was killed. It quotes the Roman Emperor Augustus as saying: "It is better to be Herod's pig than a son." It's also described in "The Infancy Gospel of James", although later scholars have cast doubt over both of these works.
However, the very respected Roman historian Josephus records many terrible acts in the life of Herod including the execution of his wife, son, and brother-in-law! Josephus also records Herod's death as taking place in 4 BCE/BC, so Jesus being born about 5-7 BCE/BC makes even more sense.
Jesus becoming a refugee and going to Egypt fulfilled some very old prophecies in the Old Testament of the Bible. The family probably didn't have to spend too long in Egypt as Herod died soon after this.
The gifts of Gold, Frankincense, and Myrrh, which were brought by the wise men to Jesus, when he and his family were living in Bethlehem, could well have been used as 'currency' during the families' escape and life in Egypt.
Frankincense and Myrrh are resins which come from trees. They have medicinal uses and were (and still are) used in many religions. They were also (and still are!) very valuable; at the time of Jesus, they were worth MUCH more than the gold!
God bless
Izzy
izzy