The concept of Israel is central to the development of Judaism and Christianity, but the boundaries of Israel and Israelite identity were the source of significant conflict throughout the Second Temple period. This chapter argues that mapping the concept of Israel in the Second Temple period requires a recursive process that first examines the biblical constructions of Israel and then evaluates how later participants appropriated, performed, and developed thaose traditions. This introduction then outlines how this work aims to accomplish these tasks and concludes with a discussion of the equally difficult term Ioudaios (Jew/Judaean) and its relation to the concept of Israel.