During WWII "The Ministry of Ungentlemanly Warfare" a.k.a. the S.O.E. gathered in Baker Street to plan sabotage and espionage missions in occupied countries, amongst them France and Norway. Christopher Lee was one of their field agents, and there is a youtube clip where he talks about killing a man in service of the S.O.E.
Several James Bond characters were inspired by the S.O.E., including M, Moneypenny and Vespa Lynd (and probably Q). Ian Fleming was not himself a part of the SOE, but he joined the Naval Intelligence where he planned more-or-less insane operations. Amongst those not carried out were plans to steal the enigma codes (less insane) and to use Aleister Crowley to trick Rudolf Hess into contacting anti-Churhill Englishmen (more insane).
The S.O.E. was, amongst other things, responsible for Operation Gunnerside where Norwegian commandos snuck into a heavily guarded military plant and blew up the entire Nazi supply of heavy water, needed to make nuclear bombs (link). Some of the commandos fled to England and Sweden, but a few stayed behind. They would later be responsible for blowing up the boat carrying the remaining heavy water to Germany, killing eighteen (link).
After the war the S.O.E. was quickly disbanded, probably because their leader was less than willing to cooperate with including it into the Foreign Office ("To have SOE run by the Foreign Office would be like inviting an abbess to supervise a brothel").
Alan Turing, the father of the modern computer and the man responsible for cracking the enigma code during WWII, killed himself with a poisoned apple.
Herman Göring's brother Albert repeatedly went against the Nazi party by amongst other thing forging his brother's signature, sabotaging the factory he was given by his brother and sent trucks to concentration camps requesting labourers for his factories. These would then "break down" somewhere so the labourers could escape. (link)