Kate O'Mara (born 10 August 1939, in Leicester) is an English film, stage and television actress. She is perhaps best known for her role as Caress Morell, Alexis Carrington's sister in Dynasty. She also played the villain, The Rani in Doctor Who.
The Rani was a renegade Time Lord and member of the Deca. A brilliant but cold neurochemist, she knew the Doctor and the Master when all three were young, and became an enemy of the former and an unwilling ally of the latter
