In August 1955 Mackie became, along with Nigel Kneale, one of the first two staff scriptwriters to be employed by BBC Television; scriptwriters had previously been employed on short-term or freelance contracts.
Mackie was the producer and writer of the acclaimed 1968 ITV historical drama series The Caesars about the Julio-ClaudianRoman emperors and later wrote the 1976 series Napoleon and Love, starring Ian Holm, about Napoleon Bonaparte's relationships with his women as a backdrop to his rise and fall as Emperor of the French.
He also wrote the script for the television adaptation of the defiantly exhibitionist homosexual Quentin Crisp's autobiography The Naked Civil Servant, for which John Hurt won the BAFTA for Best Actor in 1976.
Colleague David Croft, from Campbelltown, Argyll and Bute, recalled the King saying to Avzi. 'I think my skiing days are behind me.' ... The royal wives were then informed by royal aide Philip Mackie that 'one of the party' had died, but Diana continued ... .