British Imperial geographer and politician Sir Halford Mackinder is generally considered to be one of the founding fathers of geopolitics. The aim of this book is to provide a long overdue reconsideration of his contribution to the history of strategy. In doing so, it will provide a critical review of his geopolitical writings; an exploration of other key aspects of Mackinder's strategic thought and his ideas on grand strategy; as well as an analysis of the context of his strategic work, and its implications, both as part of a broader policy agenda and in terms of the actual impact on British policy-making.