He is Sharpe's immediate superior and was mortally wounded during the Corunna retreat. Before he dies, he gives Sharpe his heavy cavalry sabre, hoping the men will accept Sharpe, thinking Murray favored him. His death leaves Sharpe in command for the first time in his career, and it creates a power vacuum. Murray gave Sharpe one good piece of advice, to win over Harper. Sharpe eventually manages to do this, and the two men form a bond becoming the most effective team in the battalion. When the sword Murray gave to Sharpe broke in Sharpe's Sword, it was Harper who found and modified a replacement blade.
In the television movie Sharpe's Rifles, he was played by actor Tim Betinck (who also doubles as the actual 12th Earl of Portland, Viscount Woodstock and Baron Cirenceste).