From The Times
November 5, 2008
"The G&T celebrates 150th birthday with ice and a slice
London The gin and tonic, acclaimed as the world’s first cocktail, is 150 years old. The first commercial G&Ts were served to London society in 1858.
British army officers returning from India led the demand for a spot of hard liquor with a refreshing mixer and ice to have after dinner with cigars. In India they had used gin to disguise the taste of tonic, which was then a medicine made from foul-tasting quinine to fight malaria."