The development of settlement in the region between Chiusi and Volterra (northern Etruria, corresponding to the modern territory of Siena), from the Iron Age to the end of the Romanization period (9th-1st century BC), is a much-debated subject among Etruscan archaeologists. This comprehensive study attempts to analyse all the available information on the Etruscan settlements of the area to produce a coherent development model that can be adapted to cover the long time period under consideration.