But the Philistine war still continued.  Saul had incorporated in his body-guard a young shepherd of Beth-lehem in Judah of the name of David.  David showed himself a brave and skilful soldier, and quickly rose to high command in the Hebrew army, and to be the son-in-law of Saul.  His victories over the Philistines were celebrated in popular songs, and the king began to suspect him of aiming at the throne.  He was forced to fly for his life, and to hide among the mountain fastnesses of Judah, where his boyhood had been spent.  Here he became a brigand-chief, outlaws and adventurers gathering around him, and exacting food from the richer landowners.  Saul pursued him in vain; David slipped out of his hands time after time, thanks to the nature of the country in which he had taken refuge; and the only result of the pursuit was to open the road once more to Philistine invasion.  Meanwhile David and his followers had left the Israelitish territory, and offered their services to Achish of Gath; the Philistine prince enrolled them in his body-guard and settled them in the town of Ziklag.

Saul and the priests were now at open war.  Samuel, perhaps naturally, had quarrelled with the king who had superseded his authority, and had espoused the cause of David.  We are told, indeed, that he had anointed David as king in the place of Saul.  When, therefore, David escaped from the court, Saul accused the Shilonite priests who were established at Nob of intentionally aiding the rebel.  The high-priest vainly protested their innocence, but the furious king refused to listen, and the priests were massacred in cold blood.  Abiathar, the son of the murdered high-priest, alone escaped to David to tell the tale.  He carried with him the sacred ephod through which the will of Yahveh was made known, and from henceforth the influence of the priesthood was thrown against the king.

Saul had lost his best general, who had gone over to the enemy; he had employed his troops in hunting a possible rival through the Judaean wilds when they ought to have been guarding the frontier against the national foe, and the whole force of Israelitish religion had been turned against him.  There was little cause for wonder, therefore, that the Philistine armies again marched into the Israelitish kingdom, and made their way northward along the coast into the plain of Jezreel.  A battle on the slopes of Jezreel decided the fate of Israel.  The Hebrew army was cut to pieces, and Saul and his sons were slain.  One only survived, Esh-baal, too young or too feeble to take part in the fight.  Esh-baal was carried across the Jordan by Abner and the relics of the Israelitish forces, and there proclaimed king at Mahanaim.  The Philistines became undisputed masters of Israel west of the Jordan, while their tributary vassal, David, was proclaimed King of Judah at Hebron.  His nephew Joab was made commander-in-chief.

War soon broke out between David and Esh-baal.  Esh-baal grew continually weaker, and his general Abner intrigued with David to betray him into the hands of the Jewish king.  Abner, however, was slain by Joab while in the act of carrying out his treason, but Esh-baal was murdered shortly afterwards by two of his servants.  David declared himself his successor, and claimed rule over all Israel.