Fill a highball glass with ice cubes. Add all ingredients. Stir. Garnish with cucumber, lemon, orange and mint leaf.
Pimm's was first produced in 1823 by James Pimm, a farmer's son from Kent who became the owner of an oyster bar in the City of London, near the Bank of England. Pimm offered the tonic (a gin-based drink containing quinine and a secret mixture of herbs) as an aid to digestion, serving it in a small tankard known as a "No. 1 Cup", hence its subsequent name.