Commanded the 20th regiment at the Battle of Minden. Promoted to major general in the Prussian Service in the spring of 1763, he commanded Frederick the Great’s “British Legion” during the Seven Years’ war. Appointed governor of Emden.
Offered to serve in the American army (1779).
Married to Janet, daughter of Dr. George Wishart, an esteemed minister at Edinburgh. Father of Sally Beckwith, who emigrated to Philadelphia in 1782 with letters of introduction to the Baches from Franklin and William Strahan. Father of George Beckwith, a British army officer, who played an important role in talks with Alexander Hamilton preceding the negotiation of Jay’s Treaty.