Lieutenant Colonel Bertram Wigram appears in Sharpe's Siege and was described as a grey faced, dour, bloodless man who was both precise and fussy. A bureaucrat in uniform rather than a soldier, he slept in a bed every night of the war, and was known to have had his cook flogged because his dinner was served underdone.
He coldly and unsympathetically told Sharpe that his brevetted rank of Major was not accounted, and that in reality he was a superfluous captain, and he would not be taking his own men as captains did not command battalions. He added that Sharpe would rejoin his battalion as a Major only after this duty was done.
He reappears in Sharpe's Revenge as head of the tribunal convened by the Adjutant-General to inquire as to whether Sharpe and Frederickson were guilty of making off with Napoleon's treasure. It was on his watch that the men escaped the garrison.
He is given a fighting role at Toulouse which he failed. Due to insult delivered, became Sharpe's opponent in a duel - a role held by Bampfylde in the novels, a result of Sharpe's accusations of cowardice.