This chapter examines the transformation of Jerusalem in Late Antiquity, focusing on its urban development, religious significance and shifting political landscape. It traces the city’s evolution from Roman Aelia Capitolina into a major Christian centre under Byzantine rule, emphasising the role of imperial patronage in reshaping its architecture and sacred spaces. Particular attention is given to the construction of the Church of the Holy Sepulchre, initiated by Constantine and consecrated in 335. This church became the focal point of Christian Jerusalem, inspiring the development of additional religious structures, including churches on Mount Zion, on the Mount of Olives and in Bethlehem. The chapter also explores the city’s expansion under Empress Eudocia and Emperor Justinian, discussing projects such as the Nea Church and the extension of the cardo. Further discussions examine the adaptation of existing Roman infrastructure, the conversion of pagan temples into Christian buildings, and the impact of imperial policies on the city’s layout. The chapter concludes by assessing the Persian conquest in 614 CE and the subsequent Islamic takeover in 638 CE, demonstrating how Jerusalem remained a contested and sacred space throughout Late Antiquity.