Who is the grandfather of John the Baptist?

Barachiah (or Barachias), who was the father of Zechariah (or Zecharias), who was John the Baptist's father. Zechariah (Zecharias) wrote the Book of Zechariah in the Old Testament (Zechariah 1:1) and was martyred as stated by Jesus (Matthew 23:35). John the Baptist's great grandfather was the prophet Iddo.