Polo mints: 'The mint with the hole' celebrates 75th anniversary still made in Yorkshire

Harris, who married into the Rowntree family, developed many household names, including KitKats, Smarties and Aeros.

And in the late 1930s, he developed the idea for the Polo based on a similar sweet - the Life Saver, complete with hole to make it look like a rubber ring, - that was already on sale in the United States.

According to Rowntree legend, the name Polo was chosen by Harris to evoke “polar” - reflecting on the cool nature of the mint.

The course of Polo’s development, however, did not run smoothly, and the idea for the mint was indefinitely shelved during the Second World War.

But in 1948, Harris revisited the idea for the sweet - and Polos hit the shelves months later, on April 15 at a price of two pennies.

An intriguing element of the story is how the brand managed to be launched at all, given that sugar was still in very short supply at that time.

For many, it is the TV and print ads from the 1980s and 1990s that people will remember – including the Mint with a Halo and Conveyor Belt, often with the unmistakable voice of Peter Sallis.

Now, as the mint turns 75, it is still produced in York at the Nestle factory in Haxby, where machines produce up to 22,000 every minute – or a staggering 1.37m packs a day - to the same recipe that delighted mint fans in 1948.

Instantly recognisable in their green and blue wrapper, the sweets come in individual packs of 23 mints, which measure about 10 cm tall.

Over the years, other varieties of the sweet have also been introduced, including fruit Polos, however none has been as successful as the original.

Most memorably, the public was hoodwinked by a April Fool in 1995 where the company said they could no longer produce mints with holes due to EEC guidelines.

The history of mints dates back to the 18th century when they were made in the form of lozenges and tablets on the same presses as medicinal products.

Mint – given their association with natural byproducts of the plant genus Mentha – was used as a medicine for all kinds of ailments including abdominal cramps, cholera, diarrhoea, chest complaints, nasal catarrh and laryngitis.

A spokeswoman said: “Here at Nestlé in York, the confectionery team is delighted to be celebrating the 75th anniversary of Polo.

"The Mint with the Hole has been produced in the city since 1948 and remains one of the nation’s best-loved mint brands.”