Some believe that prequels are rarely a good idea; just ask any disgruntled Star Wars fan who turned their nose up at Attack Of The Clones, and they'll probably have a list prepared as to why. Look out for the name "Jar Jar Binks" scribbled down three times. Prequels are rarer in television though; the last notable one on British TV was probably Rock And Chips, the story of a young Del Boy before Only Fools And Horses, which was met with an overwhelming "Meh," from fans and critics a-like, and Breaking Bad fans are currently holding their breath over the plans for Better Call Saul. The parent show ended so perfectly, after all: but what will the spin-off be like? It's a shame really that prequels tend to be so hit and miss because they offer fantastic opportunities and, at the very least, talking points for speculation. The very best shows build incredible backstories, and these backstories could be worth exploring; fans would love to see just an episode of the Doctor's life before he stole the TARDIS, or a glimpse into the childhood of Sherlock Holmes. Of course, they're never going to happen, but here are eight shows with backstories incredible enough that actually, a prequel sounds like a fascinating idea on paper.