In the spring of 609 BC, Necho personally led a sizable force to help the Assyrians. At the head of a large army, consisting mainly of his mercenaries, Necho took the coast route Via Maris into Syria, supported by his Mediterranean fleet along the shore, and proceeded through the low tracts of Philistia and Sharon. He prepared to cross the ridge of hills which shuts in on the south the great Jezreel Valley, but here he found his passage blocked by the Judean army. Their king, Josiah, sided with the Babylonians and attempted to block his advance at Megiddo, where a fierce battle was fought and Josiah was killed.