The cocktail name comes from the Black and Tans, who were English paramilitary soldiers accused of some of the worst atrocities against the Irish during the Irish War of Independence in the early 1920s. Their nicknames stem from their uniforms, a mixture of black and khaki. The beauty of the black and tan is that you can enjoy two completely different brews in the same glass. This is the layered beer drink you see in bars across the United States, and it’s easy to make at home. This layered beer cocktail made of half stout (usually Guinness) and half pale ale (often Bass) works because the stout is less dense than the ale, so it floats atop the lighter-colored beer, creating a two-tone pint. These two beers make perfect black and tan layers in the glass if they are poured correctly. The two layers remain as you drink, separated. In Ireland, the drink is called a half and half. The term likely originated in England, where consumers have blended different beers since the seventeenth century. The tradition of blending beers can be traced to London during the 1700s when beer blends or three-threads and five-threads were consumed.