Who is John the Baptist from Life of Christ and what is their importance?

John the Baptist was Jesus' cousin, and the one who announced the Messiah's coming to the Jews before Christ began his ministry. After Christ's ministry began, John was invited to speak at a party held by King Herod. Instead of speaking of some irrelevant, trivial topic like Herod had hoped, John reprimanded Herod for marrying the wife of his brother. John was thrown in prison and eventually beheaded.