F.D.R. Martini after the American president Franklin Delano Roosevelt.
This drink varies from delicious to disgusting, depending on what's making it "Dirty". This is traditionally the liquid from a jar of olives and if using this then you'll need around 7.5ml / 1/4 oz of olive brine. (Beware jars of olives packing in oil as this produces a revolting emulsion). Instead, as indicated in this recipe, I prefer five generous dashes of The Bitter Truth's excellent Olive Bitters.
Substitute vodka for gin.
Some attribute the creation of this drink to Roosevelt: the 32nd President was a keen home bartender, although his cocktails were reportedly "horrendous" and there is no evidence that he used olive brine in his Martinis.
Also see our Dry Martini page.