On June 27, 1743, King George II became the last King of England to lead his troops in battle, when he guided them to victory against the French at the Battle of Dettingen during the War of the Austrian Succession.
Once upon a time, kings were expected to be warriors, and the military exploits of many English kings have become legendary (think Henry V at Agincourt, or Edward I and his many battles). But the practice started to die away, and by the 18th century many rulers were content to leave active battlefield commands to their most able military leaders. Despite this, there were a few kings on the battlefield during this particular war. King Frederick II of Prussia kicked the whole thing off by invading Silesia in late 1740, violating the Pragmatic Sanction of 1713, in which various European rulers agreed to accept Maria Theresa of Austria as heir to the Austrian Empire.
For a while, Frederick’s well-trained and well-equipped army did outstandingly well, and they were soon joined by the French, but then things started to fall apart when Prince Charles Alexander of Lorriane (French by birth but serving in the Imperial Army) and his troops managed to cut off the Prussians from Silesia, forcing them to fall back to Bohemia. It wasn’t quite enough to ensure Austria’s total victory in the war, and after a few more battles were won by the Prussians Maria Theresa ceded Silesia to Frederick and a peace accord was signed between Prussia and Austria, ending the First Silesian War. The War of the Austrian Succession, however, continued.
The English stepped in on Austria’s side in 1743, which was not a good year for Frederick. Some of his allies weren’t playing nicely together, and Prince Charles’s army was on the march again, with little organized resistance. King George formed an army on the lower Rhine and advanced south, where they met the army of Marshal Noailles. George was in a bad position, trapped between the Spessart Hills and the river Main, with the outlet completely blocked by Noailles’s troops. Nonetheless, George’s army was able to force their way through and the French suffered heavy losses. The battle was a victory for the British, and as the French retreated, George’s army was able to reopen supply lines to their Austrian allies, which the French had cut off. If George hadn’t been victorious, it’s likely the Austrians would have had to surrender entirely. Not long after the battle, George was distracted by the French-encouraged Jacobite Rebellion back at home and had to go deal with that.
The war dragged on until the Treaty of Aix-la-Chapelle was signed in 1748. The treaty recognized Maria Theresa’s inheritance, and Austria lost only Silesia. Although Maria Theresa owed a great debt to George’s assistance in the war, she eventually dropped Great Britain as an ally, deeming it too unreliable.