Michael Jayston played George Smiley's right-hand man Peter Guillam in the BBC's acclaimed 1979 adaptation of John le Carré's classic spy tale.
As part of the BBC's Centenary of Drama, and over four decades on, Michael now looks back on the experience, recalling what it was like working on what is still considered one of the best television series ever made, and how he held his own acting alongside one of the finest acting talents of the 20th century, the great Sir Alec Guinness.