Manasseh was twelve years old when he became king, and he reigned in Jerusalem fifty-five years. His mother’s name was Hephzibah.
Jewish Publication Society of America Version (JPS1917) - 2 Kings 21:1 >Manasseh was twelve years old when he began to reign; and he reigned five and fifty years in Jerusalem; and his mother's name was Hephzi-bah.