Rowntree's Chocolate Crisp was launched in September 1935 and cost 2d, that's 1p in today's money.
The first poster for Kit Kat appeared in 1951.
The first TV ad was in 1957 with the memorable line 'Have A Break - Have A Kit Kat' and the first colour TV ad was shown in 1969.
Kit Kat is the UK's number one confectionery brand and the number one biscuit brand.
Every five minutes, enough Kit Kats are made to out-stack the Eiffel Tower and one day's production would stretch around the London Underground.
47 Kit Kats are eaten every second in the UK.
In 1999, Kit Kat Chunky came out and was dubbed Nestlé's most successful launch of the decade.
Former rugby star Rob Andrew is crazy about Kit Kats. He had a stock of them flown out to him and his team mates in South Africa during the World Cup in 1995. Pierce Brosnan is another Kit Kat fan.