=The Final Struggle with the Philistines.= The assassination of Ishbaal by his own followers left the northern tribes no deliverer but David. All his previous training had prepared him for this great task. His acceptance of the fealty of the northern tribes was equivalent to a declaration of war against the Philistines. Regarding this important period, the biblical records are unfortunately incomplete; but from incidental references it is clear that the Philistines did not yield their claim to central Palestine without a severe and prolonged struggle. At one time they were in possession of David's own city, Bethlehem, and he was obliged again to take refuge in the border fortress of Adullam. As at the beginning of the war, they appear to have seized the series of strong fortresses on the northern border of Judah and thus to have cut off the Hebrews of the north from those of the south. The Canaanite cities from Gezer to Jebus, which doubtless acknowledged the Philistine suzerainty, completed the wall of separation. =David's Victories.= Strong in the possession of these central cities, the Philistines evidently invaded Judah directly through its two main western portals, the valleys of Sorek and of Elah. David was thus forced to depend for support chiefly upon the tribes of Judah and of the South Country. The territory in which this guerilla warfare was fought, and David's experience and skill, gave him in the end a great advantage. The Philistines were obliged to retire each year to plant and to reap their fields, and in so doing necessarily lost many of the advantages which they had gained. Repeated battles were fought and each time David gained in strength. The two decisive battles were waged in the Valley of Rephaim,^{(94)} a broad, shallow valley to the southwest of Jerusalem, from which connecting valleys ran down to Bethlehem and the south, while the main valley runs westward into the great Valley of Sorek. On this plain, with its broad, cultivated fields, the Philistines were able to mass their forces and at the same time to maintain on the west their connection with the home land. Here also David was able to rally his followers from the south and in case of defeat to have a way of escape into the neighboring wilderness of Judah. On this battle-field the final decisive engagement in Israel's war of independence was fought, and the Hebrews won a sweeping victory. As the biblical narrative states, the Philistines were compelled to abandon their northern garrisons "from Gibeon as far as Gezer." David at last was free to develop and organize that larger kingdom which was destined soon to grow into a small empire. XVII PALESTINE UNDER THE RULE OF DAVID AND SOLOMON