M16 - Secret British Intelligence agency.
They recruited him after his uncle (an agent) was KIA. He was only fourteen (something like that) and he never knew that his uncle was an agent and that his uncle had been secretly training him to becoming an agent. Example (Karate, Scuba diving, River rafting, etc. First he refused, but then agreed, taking up were his uncle left off.
In one of the books in his series he works for Scorpia, a family
(crime family) run by retired secrets agents of the cold war, both
sides. He decided to work for them after they told him that M16 had
actually murder his father and offers him a chance for
But in the end, he finds out that they lied about his dad's death and stops Scorpia from killing London's children, which included him as well.
He also worked for the CIA and the Australian secret intelligence service