Apostles of Development recounts the work of six individuals, all former classmates at Cambridge University, who helped make international development--the effort to reduce poverty and inequality around the world--into a juggernaut of the second half of the twentieth century. International development employed millions, affected billions, and spent trillions; it held the hopes of the former colonies to create an economic independence to match their newfound political one, and the plans of wealthy counties to build an enduring economic order. The six Apostles in this book include some of South Asia's best-known names, like Nobel Laureate Amartya Sen and long-serving Indian Prime Minister Manmohan Singh, as well as leading academics (Jagdish Bhagwati) and key policy-makers in both national and international circles. Taken together, this group both reflected and shaped the growing enterprise of international development from the time they left Cambridge in the mid-1950s well into the 2010s. For many years, the second half of the twentieth century was understood primarily through the lens of the Cold War. And yet, for the majority of the world, living in what was then called the Third World (and which is now called the Global South), development was a constant, while American-Soviet geopolitics only occasionally impinged upon their lives. And these six, as much as any other group, changed the way economists theorized development and aid officials practiced it. Their biographies, then, are the history of development. Based on newly available archival documents from 10 countries, and on interviews with four of the subjects, the widows of the other two, and almost 100 of their colleagues, friends, classmates, and rivals, this book combines riveting personal accounts with a sweeping history of one of the enduring human activities of the late 20th century and early 21st centuries: creating a more prosperous and equitable world.