Who is Percy Alleline from Tinker, Tailor, Soldier, Spy and what is their importance?

Percy Alleline is the chief of intelligence. He was from the Scottish lower class and had attended Cambridge. Percy worked for the Circus undercover in South America, after which, he went to India and then to Cairo. A scandal involving the Americans brought on the battle between Percy and Control, and Alleline was assigned to training recruits at the "Nursery." He takes an indefinite leave after the outcome of Smiley's investigation.