Complex sentence: He became a major in the regiment on 29 November 1750, was promoted to lieutenant-colonel of the Royal Horse Guards on 17 December 1754 and commanded the regiment in Germany during the Seven Years' War.
Split into simpler sentences: He became a major in the regiment on 29 November 1750. He was promoted to lieutenant-colonel of the Royal Horse Guards on 17 December 1754, and commanded the regiment in Germany during the Seven Years' War.