Why did the place of formerly powerful Eurasian land empires, like that of Iran, change so dramatically in global affairs over the course of the eighteenth and nineteenth centuries? This book explores this critical transitional period in Iranian history from an environmental perspective. It argues that severe ecological challenges dating to the late seventeenth century, and deepening during the post-Safavid crisis of the eighteenth century, drove a decline in the population and resource base of the Iranian plateau. This in turn shaped ongoing environmental challenges in the Qajar period and on into the 20th century. Presenting a new set of perspectives on key sources with new questions in mind, The Lion and the Sun relies upon scientific evidence such as Geographic Information System data and tree-ring analysis, as well as a careful re-engagement with existing sources. Re-interpreting court chronicles, administrative orders, local histories, geographical texts, and endowment deeds, the book reveals the way in which the relationship between imperial systems and the rest of nature formed the modern state of Iran. An important and original contribution, it will be essential reading for scholars and students of global environmental history and the modern Middle East.