Complex sentence: He then joined the Danish army, where he was promoted to Lieutenant General in 1761 and to Command of the Guards on Foot in 1762 and to Inspector General of the Infantry in 1764.
Split into simpler sentences: He then joined the Danish army, where he was promoted to Lieutenant General in 1761. He was appointed Command of the Guards on Foot in 1762 and Inspector General of the Infantry in 1764.