Brian Fordinghame is a spymaster with British Intelligence.
By that term I mean he apparently runs the show in the small bureau he is involved with. He is said to be "Chief of that important Branch of the British Secret Service known as Y1 to the authorities". As such, it is his job to decide what matters need addressing and which of his handful of skilled operatives he should assign to handle them. He comes across as an avuncular style leader, caring for his people but willing to be strong when needed.
He seems to be very much a hands-on sort of leader, getting involved in the missions, likely from not being able to let go of his days of being in the field himself.
When we meet him he has already earned, quite some time before from what I can determine, a knighthood for services rendered to the Crown, almost certainly in the years leading up to and through the Great War.
His reputation will be tested but then strengthened in the first recorded adventure when he has to switch gears from fighting against the expansionist aims of Germany's Kaiser and go up against the new still learning and still growing Soviet Union and its aims of spreading communism throughout Europe. Not helping at all will be a large contingent of Socialists in England who sing that new country's praises. Fordinghame is decidedly not one of them.
The first adversary that we have the pleasure to watch Fordinghame have to go up against is the Soviet spymaster Baron Veseloffsky and it is combating that devious genius that we get to see just how good Fordinghame is, although he does have and needs help.
After Fordinghame is able to handle the dastardly, and rather impressive Soviet spymaster in that first adventure, his problems to be solved in the next three cases will seem rather tame although not without some interesting twists.