Who is Basil Boothby from The Unlikely Spy and what is their importance?

Sir Basil Boothby is a career military intelligence officer who works for MI5, in the upper echelon of that entity. Boothby runs his own operators, manages several teams of British agents and directs Vicary and Dalton. Basil's reputation is that of a womanizer, a wealthy and ambitious man, and a networker in the system of spies. Boothby causes Vicary just as much grief as Vogel does and Boothby is on the same side as Vicary.