Yes, yes, it's a spirituous cocktail without fruit juices that best shows its crystalline beauty when stirred rather than shaken. However, it's the one...
Interestingly, Boothby (1934) contains a cocktail called Vesper. So there was already a drink called Vesper in existence almost two decades before Casino Royale. However, while it is a gin based drink, it doesn’t resemble the Vesper Martini.