Complex sentence: He was a hero of the Battle of Dettingen (1743), in Bavaria during the War of the Austrian Succession; the last time that a British monarch, in this case George II, personally led his own countrys' troops into battle.
Split into simpler sentences: He was a hero of the Battle of Dettingen (1743), in Bavaria during the War of the Austrian Succession. It was the last time that a British monarch (in this case George II) personally led his troops into battle.