This book is an argument for Middle East environmental history. Focusing on the Ottoman Empire—the longest-lasting and most important political power in the Middle East over the last millennium—and Egypt—the Middle East’s most populous and historically most lucrative region—Under Osman’s Tree shows the utility of environmental history for the study of the Middle East and the importance of the Middle East for global environmental history. The book tackles major topics in environmental history: natural resource management, climate, energy, human and animal labor, water control, disease, and the politics of nature. Throughout, it focuses on what the environmental history of the Middle East reveals about empire, the early modern period, and economic and social history, forwarding a view of empires as ecosystems of connections and linkages of mutual constitution and influence. It pays particular attention to the interactions of rural peoples with the Ottoman imperial state and how natural resource management tied the two together. Overall, it offers a novel and fresh account of the history of the Middle East over the last half millennium.