
Born November 21, 1873 in Yarmouth, England, Kell was the son of a wealthy family, provided with advanced training, speaking polish and English at an early age. Graduated from the Royal Military Academy in Sandhurst in 1892, fluent in several languages. Including French, German and Italian in addition to the Polish and English.
Served in the British military and was sent to Moscow where he quickly learned Russian. Returned to England where he married Constance Scott on April 5, 1900. Immediately thereafter was sent to China where he fought to put down the Boxer Rebellion.
Returned to London and was transferred to the War Offices' German Desk and was placed on the Committee of Imperial Defense in 1907. Was named director of MO5 (Military Operation 5), the newly developed counter-espionage department in 1909. In 1916, the name of the agency was changed to MI5. Worked alongside of and asked advice from many of the top military and security experts in Britain.
Initiated a purge of spies from throughout England. Kell ordered that the purge take place all at once in order to prevent any from escaping due to being tipped off. Many of the top spies in the country were gathered up in the purge. Later Kell would authorize the hunt for Karl Lody, the top German spy in London.