1 Kings 9:22-26

But Solomon did not make slaves of the sons of Israel; for they were men of war, his servants, his commanders, his charioteers, his chariot commanders, and his horsemen.

These were the chief officers who were in charge of Solomon’s work, 550, who ruled over the people doing the work.

As soon as Pharaoh’s daughter came up from the city of David to her house which Solomon had built for her, he then built the Millo.

Now three times a year Solomon offered burnt offerings and peace offerings on the altar which he had built for the Lord, burning incense with them on the altar which was before the Lord. So he finished the house.

King Solomon also built a fleet of ships in Ezion-geber, which is near Eloth on the shore of the Red Sea, in the land of Edom.