When Boris Johnson announced the creation of the Foreign, Commonwealth and Development Office in June 2020, he signalled the dissolution of the UK's Department for International Development (DFID) after nearly 25 years. DFID had a stellar international reputation, a respected body of expertise, and an impressive record improving lives. The Rise and Fall of the Department for International Development traces DFID's trajectory from its origins to its unravelling, distilling timely lessons for government aid institutions in the UK and beyond. DFID's lifespan coincided with a period of remarkable progress in human well-being. Rise and Fall describes DFID's role in securing these gains through an unwavering focus on its mandate to reduce poverty, under Conservative and Labour governments alike. It explains how the capture of the Conservative Party by its right-wing factions led to DFID's closure, a move now widely viewed as a mistake, and offers proposals for the next government as it defines the UK's position in a complex international landscape. Informed by the authors' own experiences at DFID as well as interviews with more than a hundred former DFID ministers and staff, The Rise and Fall of the Department for International Development offers an insider's view into the successes, struggles, and lessons of a unique government department. As leaders worldwide consider the future of international development, the book provides critical insights into the institutional structures that work best to deliver results.