Kappaban came from the Wheel of Contract on Byulna. His father was one of the ambassadors there. As a child, he never got to see anyone except other ambassadors' kids. Kappaban was kidnapped at a very young age by Lenny Kruger, who brought him to 20th century Earth, where he grew up in Liverpool as Korky Goldsmith inside a flesh suit, thinking himself human.
In 1957, he got together with two other locals, Mark Carville and James O'Meara, and formed the Common Men. The band was not particularly popular, and — by the suggestion of the Fifth Doctor — became the backing group for Aubrey Waites in 1963. This new alliance, adopting the name John Smith and the Common Men, became hugely popular within weeks, and quickly rose up to #2 on the British charts, just below the Beatles. Korky never found out he was an alien.
Alternate timeline Edit
In an alternate timeline created by Lenny Kruger, the Common Men became the most popular band in the world in the Beatles' place. They met Nyssa in 1950s Hamburg, and let her stay in their hotel for a few nights. He was immediately attracted to her, offering to sleep on the floor so that she can get the bed. Soon, though, Nyssa noticed weird patterns on his skin, and, through a blood test, discovered that he wasn't human. Together, they tried to track Lenny down so that Nyssa could return to the Fifth Doctor in 1963. Lenny eventually caught them, though, and induced amnesia on him before returning him to his hotel. He never spoke of Nyssa again, because she'd been erased from his memory.
He then encountered the Doctor proper on 31 October 1963, when he and the boys arrived in London after a plane ride, only to find hundreds of fans screaming for them outside. The Doctor warned them of Lenny walking through the crowd with an impulse laser, and James invited him for a drink.
The group met the Time Lord once more in 1967. They were at the time in a small Welsh town, promised a free private seminar with the guru Paravatar. Paravatar, secretly a retired time traveller hypnotised the musicians into revealing their true identities. After waking up, the Common Men were finally approached by Lenny, who quickly became their new manager.
According to James, when Korky once wrote a song that Mark refused to work with them on. He separated himself from his band mates after they split up in the late 1960s. By 1970, he aspired to become an actor instead.
Lenny, upset that the group disbanded and James died, further manipulated in time. In yet another timeline, the Common Men got back together. After the Doctor explained the situation to them, they agreed to help pretend that Lenny killed James, thus spreading bad word about him throughout the world. Lenny, soon to die because of this, finally let the Doctor restore the original timeline, and Korky's world returned to normal. (AUDIO: 1963: Fanfare for the Common Men)