Although quite a few Early Bronze Age sites have revealed fortifications, our knowledge of the defense systems of that period remains sketchy. Important new data were recovered during the excavation at Tell es-Sakan in the Gaza Strip in 2000 and at Tel Yarmuth in the course of the last four seasons (2003-2004, 2006-2007). They have deeply modified our understanding of the first fortification system at Tel Yarmuth, and contributed to a better understanding of the evolution of fortifications in the Land of Israel during the Early Bronze Age. Since the combined evidence of these two important sites concern all three phases of the period (Final EB I, EB II and EB III), this paper will take us back and forth to Tell es-Sakan and to Tel Yarmuth along the following parts : the first will deal with Egyptian Tell es-Sakan and the earliest fortifications in the Land of Israel ; the second part will be devoted to Tel Yarmuth and the EB II fortifications in southern Israel ; the third part will take us back to Canaanite Tell es-Sakan and the question of EB III fortifications in Israel ; and the fourth part will examine the last phase of the fortifications at Yarmuth.