1979 Cadburys Dairy Milk feat Cilla Black
In 1824, John Cadbury began selling tea, coffee, and drinking chocolate, which he produced himself, at Bull Street in Birmingham, England. John Cadbury later moved into the production of a variety of Cocoas and Drinking Chocolates being manufactured from a factory in Bridge Street, supplying mainly to the wealthy due to the high cost of manufacture at this time. During this time a partnership was struck between John Cadbury and his brother Benjamin. At this time the company was known as ‘Cadbury Brothers of Birmingham’.
The two brothers opened an office in London and in 1854 received the Royal Warrant as manufacturers of chocolate and cocoa to Queen Victoria. Around this time in the 1850s the industry received a much needed boost with the reduction in high import taxes on cocoa; this allowed chocolate to become more affordable to everyone.
Info gleaned from Wikipedia