The Road to Lausanne examines the complex political, diplomatic, and military developments that reshaped Southeastern Europe and the Near East between 1918 and 1939. Beginning with the Armistice of Moudros and the disintegration of the Ottoman Empire, the study traces the transition from imperial collapse to the emergence of the modern Turkish Republic. Central to this transformation was the 1923 Treaty of Lausanne, which provided the international legal framework confirming the results of the Turkish War of Independence and formally replacing the unratified Treaty of Sèvres. Through a detailed analysis of archival material and historiographical perspectives, this chapter explores how the Lausanne negotiations codified a new, fragile geopolitical order in the Eastern Mediterranean. It contextualises the diplomatic interplay among the Allied Powers, the ambitions of regional states, and the asymmetric negotiations that shaped the settlement. By examining the Treaty’s causes and consequences, the study highlights Lausanne not merely as a peace settlement but as a pivotal, yet contested, foundational event in the consolidation of the nation-state system in the post-Ottoman world. The chapter ultimately argues that the Treaty of Lausanne represented a legal and diplomatic conclusion of the ‘Eastern Question,’ while simultaneously inaugurating a new and uncertain chapter of modern diplomacy and minority relations in the region.