This chapter opens with four specific accounts of popular protest in Shanghai and Bombay, one pair of protests in the early twentieth century and one pair in the late twentieth century. It poses the question of why Shanghai and Bombay witnessed broad forms of popular protest for much of the twentieth century, and much narrower forms by the end of the century. It introduces key concepts, including urban political geography, urban citizenship, and urban social movements. Central claims and findings of scholars in these fields are discussed, including those of Manuel Castells, William Sewell Jr., Roger Gould, James Holston, and Charles Tilly, including Tilly’s coauthored volume on contentious politics with Doug McAdam and Sidney Tarrow. Using this literature, the chapter discusses how spatial politics can inform an understanding of contentious politics. It also provides some background on the separate but rarely connected fields of Shanghai historical studies and Bombay historical studies.