She was a companion to the Fourth Doctor
(played by Tom Baker
). She was played by two actresses.
- Mary Tamm - She only played the character for season 16 (The Key to Time season).
- Lalla Ward - She joined the Doctor at the start of the 17th season and lasted to part way through the 18th.
Romana is assigned to aid the Doctor in his search for the Key to Time (which he undertakes for the White Guardian).
After helping retrieve the key Romana regenerates into a duplicate of Princess Astra from the story "The Armageddon Factor" (much to the Doctor's annoyance) in the story "Destiny of the Daleks".
Romana leaves the Doctor to stay in E-Space in the story "Warriors' Gate" when he finally manages to leave. K9 stays with her.