The Martini is likely to be a descendant of the Martinez, a cocktail first appearing in the 1860s at the Occidental Hotel in San Francisco. Exactly when the Martini was invented though is impossible to say.
The first published recipe for a cocktail named Martini was in 1888. This version was essentially the same cocktail as the then already established Marguerite, made with equal parts Old Tom Gin (sweeter than the London Dry Gin), Vermouth, sugar syrup and a hint of Orange Curaçao and orange bitters.
Over the years the Martini became increasingly dry with the London Dry Gin taking over from the Old Tom and the bar goers starting to favor Dry Vermouth (also called French Vermouth) over the sweet one. At the turn of the 19th century Martini & Rossi started marketing a Dry Vermouth on the American market with the tag line “It’s not a Martini unless you use Martini”.
Today a Martini, or Dry Martini, can mean anything from a 1:5 ratio to a 1:32 ratio or even just a quick Vermouth spray with an atomizer on the inside of the glass before pouring ice cold gin.
When ordering a Martini it might be good to know that James Bond’s catchphrase “Shaken, not stirred” will render the cocktail cooler than stirring it but the reason a bartender will, almost by default, stir it instead is that this way you will achieve a less cloudy Martini without shards is ice floating on the surface.
So whether you prefer it 1:1, 1:3, 1:5, 1:7, 1:32, with a lemon twist or an olive (or three), having it dirty (with a dash of olive brine), with a pickled onion (called a Gibson) or any other way. There is basically a Martini for everyone.