Rattus has an idea that might make him millions – he is going to launch a streaming service. However, to make Ratify a success, he is going to need some great songs from history. 

Horrible Histories celebrates 100 years of the BBC with this special episode. What was the secret of looking great on a 1930s TV show? How did the BBC try to defeat the Nazi's using regional accents? And just what was a kangaroo doing at the launch of BBC2? Plus our end song takes us through the history of children's TV.