This chapter introduces Central Asia in historical perspective, focusing on the ways in which the region has been spatially understood and delimited from both within and without. What is Central Asia, and how does the term relate to Middle Asia, Turkestan, Eurasia, and other common descriptions and ways of thinking that have been applied to the region? Far from merely presenting a history of terms, however, this chapter explores how these categories reflect different facets, historical epochs, and sub-regions, along with the shifts in thinking, local politics, and state administration that have occurred. The overview focuses on the nineteenth and twentieth centuries. At the outset, however, the chapter addresses a number of key issues that have long dominated discussions of the region.