Albert Barnes Commentary 2 Chronicles 23:20

"And he took the captains of hundreds, and the nobles, and the governors of the people, and all the people of the land, and brought down the king from the house of Jehovah: and they came through the upper gate unto the king`s house, and set the king upon the throne of the kingdom." — 2 Chronicles 23:20 (ASV)

The high gate - See the note on 2 Kings 11:19.