Key military developments occurred in the early modern period, during which armies evolved from troops of medieval knights to Napoleon's mass levies. Firearms impelled change, necessitating new battlefield tactics and fundamentally altering siege and naval warfare. The size and cost of military forces expanded enormously, and new standing armies underpinned the growing absolutist power of princes. Academic experts from both sides of the Atlantic discuss these developments in up-to-date overviews of the most important topics. In the European context chapters cover the medieval legacy, Spain, the Thirty Years War, Prussia, the ancien regime, and the Napoleonic Wars, as well as the development of sea power across the period. In the wider world contributors discuss the Ottoman Turks, colonial wars in America, and the American Revolution, concluding with a review of early modern warfare beyond the western sphere of influence.