All these were joined together in the vale of Siddim, which is the salt sea.

The latter five came as allies to the Valley of Siddim (that is, the Salt Sea).

And there went out the king of Sodom, and the king of Gomorrah, and the king of Admah, and the king of Zeboiim, and the king of Bela (the same is Zoar;) and they joined battle with them in the vale of Siddim;

Then the king of Sodom, the king of Gomorrah, the king of Admah, the king of Zeboiim, and the king of Bela (that is, Zoar) marched out and arrayed themselves for battle in the Valley of Siddim