The Vesper Martini, sometimes simply known as Vesper, is a variant of the classic Dry Martini created by James Bond, and therefore Ian Fleming, in 1953.
The drink was indeed invented by Fleming himself, and featured in the 1953 James Bond novel Casino Royale. The entire scene which spawned the creation of the cocktail has been recreated in the 2006 Casino Royale film featuring Daniel Craig.
In theory, the gin must be Gordon’s, but in reality, any gin can be used. Speaking of which, the first thing you need to know about the recipe of the original Vesper Martini is that it does not actually include Martini. I know.
It’s made with gin, vodka and Kina Lillet, a French wine which is more or less the French equivalent of vérmot (also known as vermouth), which was created in Turin, Italy, in 1786. The main issue with Kina Lillet is that you can never find it. I have ordered a Vesper in several bars and cocktail lounges in different countries and the answer is always invariably the same, “Ok, except we haven’t got Kina Lillet”.
That’s the reason why modern bartenders have created new versions, usually with vermouth or sometimes with Martini, that reproduce, more or less accurately, the original taste. Of course, I’ve no idea what the original taste was because I was still a long from being born in 1953.
Vesper is a very strong cocktail. It mixes gin and vodka, which are pretty strong in their own right, and it doesn’t include any non-alcoholic elements save for a thin slice of lemon peel. It doesn’t even include ice.
The best Vesper I’ve ever tried was made by a very young bartender, who claims to have worked for Zlatan Ibrahimovic at a yacht party in the Mediterranean, at Chez Moi, which is a very unsettling and decadent "dance & nightclub" in Florence.