Building 100 provides a glimpse into the life of the Jerusalemite elite and testifies to the expansion of the city’s administrative quarter, which began in the late ninth century and culminated in the seventh century BCE. During this period, royal officials settled on the slopes of the City of David, below the summit of the hill that accommodated most of the key state institutions—the Temple, the palace, and the priestly and royal courts of these respective institutions. In particular, the city’s western slope became an area of wealth and importance, a phenomenon that reached its peak in the Hellenistic and early Roman periods (fourth century BCE–first century CE), when the eastern slope was completely abandoned while the western slope continued to be used for new public buildings. The main reason for this shift was the creation of the Siloam Tunnel in the late eighth or early seventh century BCE, which diverted the city’s main water supply from the Gihon Spring on the city’s eastern slope to the Siloam Pool at the southern end of the central valley. With this change, the central valley (also known as the Tyropoeon Valley) became the main route connecting the new pool with the area of the Temple Mount, thereby making the western slope the heart of Jerusalem’s transformed urban center.