He returned to Doctor Who in 1976, delivering a totally different but equally transfixing performance as the wonderfully monstrous Mehendri Solon in The Brain of Morbius. Two years later he was back as Fenner in the Key to Time story, The Power of Kroll.
Aside from his work on Doctor Who, Philip's credits include an array of TV favourites including The Saint, The Avengers, UFO and Dad's Army. He also received critical acclaim as the lead in The Life and Times of David Lloyd George and as DCI Noel Bain in the long-running series, A Mind to Kill.
But for Doctor Who fans, he will forever be the mad, murderous scientist playing the perfect foil to the Fourth Doctor and the sinister, spell-binding War Lord in the Second Doctor's swansong adventure. Much admired by fans of Doctor Who and great British drama in general, he'll be missed and remembered with enduring fondness.
You can read more about Philip Madoc, including tributes from those who knew him, here .