Romana, short for Romanadvoratrelundar, was portrayed by Mary Tamm and Lalla Ward in two incarnations of the character.
Romana I Traveled with the Doctor between The Ribos Operation and The Armageddon Factor.
Travelling alone after the departure of Leela and K9, the Doctor’s TARDIS was stopped in mid-flight by the enormously powerful White Guardian, who wanted the Doctor to help locate the six scattered segments of the Key to Time.
To assist the Doctor, he gave him a new companion: a Time Lord named Romanadvoratrelundar, (or “Romana” for short). Although intelligent and sophisticated, Romana was a little haughty, and her naivety often tried the Doctor’s patience. It also irked him that she was somewhat more qualified than he was! Their quest to assemble the Key completed, Romana chose to regenerate.
Romana II joined her fellow Time Lord, the Doctor, to track down the scattered segments of the Key To Time. After finishing their mission, Romana regenerated, apparently on a whim, and in the form of Atrios’s Princess Astra!
The new Romana was more independent and self-assured, but was still not above teasing the Doctor with her superior knowledge. After a series of adventures, including a trip to the Daleks’ home planet, Skaro, the TARDIS traveled into Exo-Space, where Romana was infected by the Marsh Spiders on the planet Alzarius. Shortly afterwards Romana decided to stay in Exo-Space, with K9, to help the Tharils free themselves from slavery.