George III's collection of military maps comprises some 3,000 maps, views and prints ranging from the disposition of Charles V's armies at Vienna in 1532 to the Battle of Waterloo (1815).

Most notable among these are the military maps, prints and drawings collected by his uncle, William Augustus, Duke of Cumberland (1721–65), particularly during his period as Captain General of the British army during the War of the Austrian Succession (1743–8) and the Seven Years War (1756–63).

The second major collection, bought by George III in 1763, was that of the military prints collected by the Italian art patron, Cassiano dal Pozzo (1588–1657). In addition to these, George III acquired hundreds of maps of contemporary conflicts, such as the American War of Independence (1775–83), and the French and Napoleonic Wars (1792–1815).