Romana
Romana, short for Romanadvoratrelundar, is a fictional character in the long-running British science fiction television series Doctor Who. A Time Lord from the planet Gallifrey, she was a companion of the Fourth Doctor. more...
As a Time Lord (or Time Lady), Romana was able to regenerate, and therefore the character had two incarnations with somewhat different personalities. These different incarnations have been dubbed Romana I and Romana II by fans. Romana I was played by Mary Tamm from 1978 to 1979. When Tamm chose not to sign on for a second season, despite optimistic prodding on the part of the show’s producers, the part was recast. Romana II was played by Lalla Ward from 1979 to 1981.
Romana I
The White Guardian originally assigned Romana to assist the Doctor during the quest for the Key to Time, which was a series of linked serials which constituted the whole of Season 16 (1978-79). Romana first appeared in The Ribos Operation, and was intended to be a contrast to the savage Leela, her predecessor. Romana was initially played as haughty and somewhat arrogant, looking down upon the Doctor (whom she considered to be her academic inferior) and responding to his initial resentment at her presence with icy put-downs. However, she soon gained an appreciation for the Doctor's experience and sense of adventure, and began to respect him as a teacher.
Over the course of Season 16, Romana appeared to take some of the characteristics of the screaming "damsel in distress", much to the annoyance of the actress who played her. When Tamm decided not to return to the role, Romana regenerated into Romana II at the start of Season 17, emerging with a different physical appearance and a lighter personality.
The suddenness of the regeneration scene was also dictated by real life events. Although Tamm had left the show on relatively good terms and did not object to returning for a brief regeneration scene, by the start of Season 17, she was very visibly pregnant, making her return impractical.
Romana II
The introduction of Romana's second incarnation in Destiny of the Daleks, a script credited to Terry Nation, but with several additions and alterations by script editor Douglas Adams, treats the concept of regeneration humorously. At the beginning of the serial, Romana changes bodily forms several times, rather like someone casually trying on different outfits, before deciding to take the form of Princess Astra, who had been played by Lalla Ward in the final serial of Season 16, The Armageddon Factor. This regeneration scene has been controversial with some fans: see below.
Romana II enjoyed a more intimate relationship with The Doctor than her predecessor, to the point that fans have assumed a romantic relationship with the Doctor. Although a relationship was never explicitly shown or intended by the writers, many fans have found the signs of a romantic relationship particularly evident in the story City of Death, perhaps reflecting the real-life romance between Tom Baker and Lalla Ward which reportedly blossomed during the production of that story, leading to their brief marriage.
Read more at Wikipedia.org