In 1976, Eric Nicoli spotted a gap in the confectionery market and used the cheap cocoa from Rowntree’s favourable futures market position to launch Yorkie. Production was at York and Norwich (until 1994).
The Yorkie bar, a chunkier alternative to Cadbury’s Dairy Milk, was aimed at men. In the 1980s for example, toy lorries with the Yorkie bar logo were manufactured by Corgi, and television advertisements for the Yorkie bar featured truck drivers. In 2001, the advertisement campaign made this more explicit with the slogan and wrapper tagline It’s not for girls, which caused controversy. Nestlé also received complaints about this campaign from Norwegian and UK people, who found it sexist and distasteful. Special versions for use in Ministry of Defence ration packs read It’s not for civvies. In 2006 a special edition that was for girls was sold, wrapped in pink. Aside from the original milk chocolate bar, several variants are available, such as “raisin and biscuit” flavour, “honeycomb” flavour, and Yorkie Ice Cream.
For a time, trains arriving at York railway station would pass a billboard which read “Welcome to” and then a picture of a Yorkie bar, with the end bitten off, so it read “Welcome to York” (and beneath it, the slogan “Where the men are hunky and the chocolate’s chunky”).
Yorkie was originally composed of seven chunks of chocolate, which was reduced in the 1990s to six with each chunk featuring one letter from the Yorkie name. At the same time, the packaging was changed from the original foil wrapping with paper surround to the current style, which projects at the ends giving it the appearance of being the same length as the original on the shelf. More recently, in an effort to further reduce cost, the number of chunks has been reduced to five, with “Yorkie” written in full on each chunk.
In 2002, Yorkie bars were 70 grammes. This had been reduced to 64.5 grammes by 2010, and was reduced further to 61 grammes in 2011 and then 55 grammes later that year. Yorkie King size bars have also reduced in size. In 2011, standard Yorkie bars became available in 3 packs.
Info gleaned from Wikipedia