The ancient Thapsacus, an important city on the western bank of the Euphrates, which constituted the northeastern extremity of Solomon's dominions, 1 Kings 4:24 . The ford at this place being the last one on the Euphrates towards the south, its possession was important to Solomon in his design to attract the trade of the East to Palestine. Hence the building of Tadmor on the desert route. Perhaps the same city is meant in 2 Kings 15:16 , though some understand here a city of the same name near Samaria.