Ryan Stiles and Colin Mochrie grew up together and are best friends in real life, even before being cast on Whose Line Is It Anyway? UK version.
Began as a radio program on BBC Radio 4 in 1987. In fact the reading of the credits in a style of the host's choosing started there since the credits couldn't been seen anyways.
In the mid-1990s, the series filmed occasional episodes in the United States. The popularity of these outings led to an American version of the series being launched in 1998. The final season of the British program was in fact filmed on the set of the American version. By that time, aside from the host, the majority of the performers were North American (including the musician), with only the occasional British performer guest-starring, whereas initially it had been very much the other way around.
The animation of the opening titles the show eventually settled on is based on an Italian cartoon shorts series called La Linea (direct translation 'The Line'), which was very popular in Europe from the mid-seventies well into the nineties. It featured almost the exact same type of chalkboard 'single-line' drawn character, only with a round nose rather than pointy.