Ian Don Marter (28 October 1944 – 28 October 1986) was an English actor and writer, known for his role as Harry Sullivan in the BBC science-fiction television series Doctor Who from December 1974 to September 1975, with a non-regular, one-serial return in November and December 1975. He sometimes used the pseudonym Ian Don. Marter died suddenly in 1986.
Born in Warwickshire, the son of Donald Marter and his wife Helen Donaldson, Marter graduated from the University of Oxford in 1969 and started work at the Bristol Old Vic theatre, where he served as a stage manager in addition to acting in minor stage roles.
In 1971, Marter auditioned for the regular role of Captain Mike Yates in the eighth season of Doctor Who. He was offered the part, but was unable to accept due to a prior commitment. The production team were sufficiently impressed that they kept him in mind and cast him in a supporting role in the 1973 story Carnival of Monsters, broadcast as part of the tenth season of the programme.
Guilty for nothing, treason took place
The Caesar's effacing thy grace
Once a commander but life's turning fast
Into a dark world you're cast
Pay the price for guiltless crimes
Enter the great arena
Raise thy sword, the martyr you are
Kill or be killed at once
When your fate is in the light
In a dome of watching eyes
You fight to keep thy honour
But you can't forget the lies
Pride once lost...the holocaust
The entrance to martyria
Gone are the days of imperial fame
When pride rose along with your name
Your future was lost in the merciless raid
When your loved ones were brutally slayed
Here you stand embraced with pain
There's no retreat or shelter
Keep thy trust, there's glory to find
Fight with no fear in mind
See through the lies
I'm your destined sacrifice
For the glory of Rome