Toward the end of the Iron I, the vast majority of the many rural villages excavated in the highlands were abandoned. At the same time, a handful of settlements began to grow into fortified towns. Why did these dramatic changes take place at this time, and what is the relationship between these two phenomena? The chapter reviews the evidence and evaluates the various possible explanations for such widespread abandonments, including climate change, nomadization, incentives to move to other regions, forced resettlement, death, and security (external threats), and concludes that the first phase of this abandonment could have only been a result of an external threat (the second phase of the abandonment will be discussed in subsequent chapters, and especially Excursus 12.1). The chapter then identifies the threat with the Philistines, analyzes the nature of Philistine–Israelite interaction, and assesses the impact of the Philistine pressure on social complexity in the highlands and the emergence of leaders there. This is also the phase in which the first Iron Age fortifications appear in the highlands. Taken together, these changes signify the emergence of the Israelite monarchy toward the end of the Iron Age I and the transition into the Iron II.