How the chocolate bar became a million dollar idea
14 February 2019 Last updated at 23:57 GMT
Nowadays, the world spends close to $100bn a year on chocolate bars, making them one of the most popular snacks in history.
But for centuries, chocolate had only been a drink. No one knew a way of making it into a solid food. That is until a 19th Century Englishman - Joseph Fry - worked out how to do it.
Aaron Heslehurst now explains.
Video producer: Jeremy Howell