Use of the name "Kit Kat" or "Kit Cat" for a type of food goes back to the 18th century, when mutton pies known as a Kit-Kat were served at meetings of the political Kit-Cat Club in London.
The origins of what is now known as the "Kit Kat" brand go back to 1911, when Rowntree's, a confectionery company based in York in the United Kingdom, trademarked the terms "Kit Cat" and "Kit Kat". Although the terms were not immediately utilised, the first conception of the Kit Kat appeared in the 1920s, when Rowntree launched a brand of boxed chocolates entitled "Kit Cat". This continued into the 1930s, when Rowntree's shifted focus and production onto its "Black Magic" and "Dairy Box" brands. With the promotion of alternative products the "Kit Cat" brand decreased and was eventually discontinued. The original four-finger bar was developed after a worker at Rowntree's York Factory put a suggestion in a recommendation box for a snack that "a man could take to work in his pack".The bar launched on 29 August 1935, under the title of "Rowntree's Chocolate Crisp" and was sold in London and throughout Southern England.
The product's official title of "Rowntree's Chocolate Crisp" was renamed "Kit Kat Chocolate Crisp" in 1937, the same year that 'Kit Kat' began to incorporate "Break" into its recognisable advertising strategy.The colour scheme and first flavour variation to the brand came in 1942, owing to World War II, when food shortages prompted an alteration in the recipe. The flavour of "Kit Kat" was changed to "dark"; the packaging abandoned its "Chocolate Crisp" title, and was adorned in blue. After the war the title was altered to "Kit Kat" and resumed its original milk recipe and red packaging.
The Hershey Company has a licence to produce Kit Kat bars in the United States which dates from 1970, when Hershey executed a licensing agreement with Rowntree. Nestlé, which has a substantial presence in the US, had to honour the licensing agreement when it bought Rowntree in 1988 which allowed Hershey to retain the Kit Kat licence so long as Hershey was not sold. As Kit-Kat is one of Hershey's top five brands in the U.S. market, the Kit Kat licence was a key factor in Hershey's failed attempt to attract a serious buyer in 2002.
Variants in the traditional chocolate bar first appeared in 1996 when "Kit Kat Orange", the first flavour variant, was introduced in the United Kingdom. Its success was followed by several varieties including mint and caramel, and in 1999 "Kit Kat Chunky" was launched and received favourably by international consumers. Variations on the traditional "Kit Kat" have continued to develop throughout the 2000s. In 2000 Nestlé acquired Fujiya’s share of the brand in Japan, and also expanded its marketplace in Japan, Russia, Turkey, and Venezuela, in addition to markets in Eastern and Central Europe. Throughout the decade 'Kit Kat' has introduced dozens of flavours and line extensions within specific consumer markets, and celebrated its 75th anniversary on 10 October 2009.
The traditional bar has four fingers which each measure approximately 1 centimetre (0.39 in) by 9 centimetres (3.5 in). A two-finger bar was launched in the 1930s, and has remained the company's best-selling biscuit brand ever since. The 1999 "Kit Kat Chunky" (known as "Big Kat" in the US) has one large finger approximately 2.5 centimetres (0.98 in) wide. Kit Kat bars contain varying numbers of fingers depending on the market, ranging from the half-finger sized Kit Kat Petit in Japan, to the three-fingered variants in Arabia, to the twelve-finger family-size bars in Australia and France. Kit Kat bars are sold individually and in bags, boxes and multi-packs. In Ireland, the UK and America Nestlé also produces a Kit Kat Ice Cream, and in Australia and Malaysia, "Kit Kat Drumsticks".
In 2010 a new £5 million manufacturing line was opened by Nestlé in York, UK. This will produce more than a billion Kit Kat bars each year.