Q: WHAT YEAR DID AZARIAH/UZZIAH 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 743 BC.
On the Hebrew calendar, sometimes called the biblical calendar, the year was 3304 AM.
2 Kings 15:1-2 – 1 In the twenty and seventh year of Jeroboam king of Israel began Azariah son of Amaziah king of Judah to reign. Sixteen years old was he when he began to reign, and he reigned two and fifty years in Jerusalem. And his mother's name was Jecholiah of Jerusalem.