Did John the Baptist's execution have anything to do with Jesus' ministry?

Answer 1

No. Herod Antipas executed John the Baptist because he had publicly criticised Antipas' marriage to Herodias, which took place in 34 CE, and Herod feared an uprising if John were allowed to continue his criticisms and therefore had him executed. John the Baptist also died long after the ministry of Jesus in 35 or 36 CE, in the faraway castle of Macherus. The relevant text from Book 18 of Antiquities of the Jews says:
"Now many people came in crowds to him, for they were greatly moved by his words. Herod, who feared that the great influence John had over the masses might put them into his power and enable him to raise a rebellion (for they seemed ready to do anything he should advise), thought it best to put him to death. In this way, he might prevent any mischief John might cause, and not bring himself into difficulties by sparing a man who might make him repent of it when it would be too late. Accordingly John was sent as a prisoner, out of Herod's suspicious temper, to Macherus, the castle I already mentioned, and was put to death."

For some reason, the gospels place the death of John the Baptist at a party in Galilee in about 29 CE, when Jesus was only beginning his ministry. The gospels agree that John was arrested because of his criticism of Herod's marriage, but say that the daughter of Herod's new wife, Herodias, entranced him with her dancing and he offered to give her anything she wanted. Herodias wanted John the Baptist dead for criticising her marriage, so she told her daughter to ask for John's head on a platter. Although differing on the time, place and reason for the death of John, the gospel account agrees that John the Baptist's execution had nothing to do with Jesus' ministry.

Answer 2

Another answer from our community:

He died because of his beliefs. He was doing the Lord's work.