Tinker, Tailor, Soldier, Spy. John Irvin. BBC Worldwide (1979)

Superb spy drama with a top notch cast. George Smiley was retired from British Intelligence on the foot of a failed operation to identify a traitor and has been asked to conduct an investigation when it becomes clear that there probably is one. Smiley starts to trace back through the recent history of the service and the details of the failed operation and he slowly uncovers an a deeply rooted conspiracy. The series unfolds at a steady pace, it grips like a python and builds to a bitterly satisfying conclusion.
Alec Guinness as George Smiley leads the superb cast as the brilliant spymaster whose investigation brings him face to face with the greatest failures of his own life. His mild and modest demeanour hides a steely intention to locate his enemy and rescues his beloved service from a traitor. Alec Guinness is masterly as a man who is supremely competent as a spy and so uncertain outside of that role. He does not dominate the series as the rest of the cast are also superb, from Hywel Bennett as the man who starts the process, Anthony Bate as the senior Civil Servant who is trying to control the mess before it becomes too widespread, among others.
The shabby exhaustion of the 1970s is captured beautifully, the Cold War was in full force and there was a sense of decline and wasting at large. This is a gripping portrait of a world where deceit and treachery are the tools of the trade and brutal bureaucracy of professional spying. Televion drama of the highest order.