This new concise history by one of Britain's leading military historians explores the British army from the creation of a permanent standing army in the seventeenth century to the present. It sets the institutional development of the British army, and its often ambiguous relationship with state and society, as well as the army's wider political, social, economic, and cultural role within international, imperial, national, regional, and local contexts.

An army exists to fight, however, and the British army's story cannot be separated from those wars and conflicts that have punctuated its evolution. Consequently, attention is also paid to the army's commanders, operations, and battlefields from the Wars of the Three Kingdoms in the seventeenth century to Iraq and Afghanistan in the twenty-first.

Beckett traces the army's evolution through five chronological phases: the standing army of the seventeenth century and its antecedents, the national army of the eighteenth century, the imperial army of the nineteenth century, the people's army of the two world wars, the era of national service, and the return to a small professional army fulfilling a global role envisaged by successive governments in the twenty-first century at a time of rapidly changing social attitudes towards the utility of force, that pose a challenge to the army's traditional core values.