Q: WHAT YEAR DID MANASSEH BEGIN HIS REIGN IN JUDAH?
A: IT DEPENDS WHAT CALENDAR YOU ARE USING!
On the Gregorian calendar (the one you might have on your wall) the year was 633 BC.
On the Hebrew calendar, sometimes called the biblical calendar, the year was 3414 AM.
2 Kings 21:1 – Manasseh was twelve years old when he began to reign, and reigned fifty and five years in Jerusalem. And his mother's name was Hephzibah.