Darko Kerim (also referred to as Kerim Bey, where Bey is the equivalent of the English "Mister") was Head of the British Secret Service's "Station T" in Istanbul and a prominent ally of James Bond. He is known by the British secret service by the letter "T" in the same way that Miles Messervy is known as "M".
Darko Kerim was born in Trezibond (now Trabzon) to a Turkish father, a fisherman, and an English mother, a governess. At the age of twenty he too was a fisherman, and was recruited into MI6 by a Major Dansey who wanted information about the Russian oil installations and naval base at Batoum, only 50 miles away. He later infiltrated Soviet Georgia as a strongman and wrestler in a travelling circus.
He became Head of Station T in Istanbul in the late 1930s. He uses his many sons and uncles as agents, running a business trading spices as cover. In his office Bond notices certificates showing that he has two Mentions in Dispatches and the military OBE. He is described as 6 feet 2 inches (1.88m) tall, powerfully built, dark, with a broken nose. He smokes Turkish cigarettes (naturally), and has an insatiable appetite for raw food, coffee, alcohol, and women.
He meets Bond and arranges for false papers in order for Bond and Tatiana Romanova to leave the country. Later he takes Bond through a rat-infested tunnel to a periscope he had installed below the Russian Embassy. This gives Bond his first look at Tatania. He then takes Bond to the Gipsy Camp (also used by Kerim as agents) where they witness the girl-fight, before being attacked by "The Faceless Ones", Bulgarian thugs employed by the Russians.
Afterwards Kerim (with Bond's help) kills Krilencu, leader of the Bulgars, with a sniper rifle concealed in a walking stick, as the Bulgarian attempts to leave his apartment using an escape hatch hidden behind a film poster. He then accompanies Bond and Tatania on the train out of Turkey. He arranges for two of the three MGB men following Bond to be arrested, but is stabbed to death by the third, killing his assassin in the process.