The twenty-first season of British science fiction television series
Doctor Who began on 5 January 1984 with the 5th Doctor (Peter Davison)
serial Warriors of the Deep, and ended with Colin Baker's first serial
The Twin Dilemma. For only the second time (the first being during
season 4), the entire TARDIS crew changed over the course of a single
season.Peter Davison makes his final regular appearance as the Doctor
in The Caves of Androzani. Colin Baker makes his first full appearance
as the Doctor in the final serial The Twin Dilemma.Janet Fielding
(Tegan Jovanka) and Mark Strickson (Vislor Turlough) continue their
roles as the Fifth Doctor's companions for their final season, Janet
Fielding leaves in Resurrection of the Daleks and Mark Strickson
departs in Planet of Fire. New companion Peri Brown played by Nicola
Bryant makes her first appearance in Planet of Fire. Doctor Who (season 21) Biography, NetWorth, Height, Age, Weight, Family, Married, Son, Daughter