Guy Fosse is an agent with the British Secret Service.
More accurately, he is an agent working for a man named Sir Richard Ordish, known to the many who work for or with him and do not like him as Tricky Dicky. Ordish is the Coordinator for the British Secret Services and as such has oversight responsibilities for MI-5, MI-6, and Special Branch. He also has an assortment of agents who work directly for him. Fosse is one of those agents.
Fosse is the epitome of what people would expect an agent for British Intelligence to not be. At thirty-three years of age when the first book about him begins, he is considered by most to be a playboy-photographer, interested only in his own gratifications. He has a winning smile and an easy manner about him that says to observers he is used to getting what he wants and might become petulant if thwarted. He is quick with a grin or a sneer and loves to travel about the world ostensibly taking photos of whatever pleases him. The truth, though, is considerably different and the façade that he presents is only to make his true work less visible.
He had started his adult life much as the perception of him would indicate. He was educated at a private school but chose to not go to university when he matured but instead to attend an art college in London specializing in photography. Once he was through, he got himself an apprenticeship with a major London studio to learn the ropes. His private wealth from a fairly wealthy father allowed him the opportunity to work for next to nothing and the contacts he had through his recently deceased parent and the baronetcy that came with it got him into the doorway.
Taking a job as a photographer on a cruise ship to further his journeyman training, he met and fell deeply in love only to have the lady run off some time later with his best friend. The betrayal sobered him considerably and took from him any desire for settling down. He started a period of travelling wherever a need for a photojournalist could take him - the greater the danger, the better he seemed to like it.
It was this recklessness that brought him to the attention of British Intelligence and he was offered a position with DI-6 (MI-6). For the next four years he would be their roving man on the spot, taking pictures for the home newspapers while doing the missions that were his real reason for being there. When the desire for constant travel finally worked it way out of him, he moved to London and set up his own studio. It was from this location, though, that he would often take the odd job from his newest boss, Ordish.
Note: The noted bibliographer Allen Hubin has another book listed in the series: The Treachery Trade, 1977, taking place in Greece. I have not yet confirmed this.