It’s the drink of summer, packed with both ice cubes and cubes of fruit and cucumber, the Pimm’s cocktail – or No. 1 Cup, is consumed at cricket or polo matches, picnics and back garden barbecues … if you’re British, that is.

And the fact that the No. 1 designation is part of the drink’s name gives an indication that there are other numbers in the Pimm’s range. During the drink’s history, there have been seven different variations but only Nos. 1, 6 and 3 remain in production. What set them all apart was the spirit base used.

The No. 1, the original, is gin based and has been since inception in the 1840s. The No. 2 Cup, introduced to market in the 1930s until its demise in 1970, was based on Scotch whisky. The No. 3 cup was released at the same time as No. 2 – the 1930s, also withdrawn in 1970 but then revived in 2004 and remains current. It’s based on brandy and is infused with spices and orange peel, also known as the Pimm’s Winter Cup.

For the pirate lovers, Pimm’s No. 4 Cup was dark rum based but was only on the market for 35 years from 1935 to 1970. Interestingly, the No. 5 was introduced at the same time as the No. 4 and was intended specifically for the Canadian market – as an alternative to the No. 2, having rye whiskey rather than Scotch at its heart.

A latecomer to the stable was vodka-based No. 6, which made its appearance in 1964 before being discontinued in 1970 and then reappearing in 2004. Equally short-lived was Pimm’s No. 7, geared at the American market and its affection for tequila. It too died in 1970. Cocktail and alcohol history enthusiasts search far and wide for any remaining bottles of this unicorn because it was only ever made in very small quantities.

So what is Pimm’s? It’s a dark brown drink with a light citrus and spice flavour. Its alcohol by volume is 25% and once mixed with the components for a Summer Cup, that becomes diluted to around 5% - or about the same as a beer or half that of wine.

The story goes that the originator of the drink, James Pimm, used to run an oyster bar in the City of London, near the Bank of England. The Kentish farmer’s son used a secret mix of herbs and liqueurs to mix up a drink to aid digestion, and served it in a tankard, known as a No. 1 Cup. See where the name came from? It became so popular he began bottling and selling it for three shillings a bottle. By 1865 it was a commercial proposition and a thriving business. Nowadays, the brand is part of the mammoth Diageo stable.

The Pimm’s Summer Cup of No. 1 Cup is usually mixed with lemonade, lots of ice and a range of chopped fruits, generally apple, strawberry, orange, lemon and mint – and, of course, ribbons of cucumber. It’s also acceptable to substitute ginger ale for the lemonade.

Twists on the Summer Cup are many with the lemonade substituted by sparkling wine or Champagne in the Pimm’s Royal Cup. And to make a Pimm’s Winter Cup heated or warmed apple juice takes the place of the lemonade.