In the Battle of Dettingen, George II becomes the last reigning British monarch to participate in a battle.

The Battle of Dettingen (German: Schlacht bei Dettingen) took place on 27 June 1743 during the War of the Austrian Succession at Dettingen in the Electorate of Mainz, Holy Roman Empire (now Karlstein am Main in Bavaria). It was fought between a Pragmatic Army, composed of the British, Hanoverian and Austrian troops, and a French army commanded by the duc de Noailles.

While the Earl of Stair exercised operational control, the Allied army was nominally commanded by George II, accompanied by his son the Duke of Cumberland. As a result, it is now best remembered as the last time a reigning British monarch led troops in combat.

Despite being an Allied victory, the battle had little effect on the wider war, and has been described as 'a happy escape, rather than a great victory.'