Charlie and the Chocolate Factory features the adventures of young Charlie Bucket inside the chocolate factory of eccentric candymaker Willy Wonka. The story was originally inspired by Roald Dahl's experience of chocolate companies during his schooldays. Cadbury would often send test packages to the schoolchildren in exchange for their opinions on the new products. At that time (around the 1920s) Cadbury and Rowntree's were England's two largest chocolate makers, and they each often tried to steal trade secrets by sending spies into the other's factory, posing as employees. Because of this, both companies became highly protective of their chocolate making processes. It was a combination of this secrecy and the elaborate, often gigantic, machines in the factory that inspired Roald Dahl to write Charlie and the Chocolate Factory.