A dark style of beer originating in London in the 18th century, descended from brown beer, a well-hopped beer made from brown malt. Porter was the first beer to be aged at the brewery and dispatched in a condition fit to be drunk immediately. It was the first beer that could be made on any large scale and the name is thought to come from its popularity with street and river porters.

The history and development of stout and porter are intertwined and they are sometimes considered synonymous. The term stout was initially used to indicate a stronger porter than other porters issued by an individual brewery.

Shortages of grain during WWI led to restrictions on the strength of beer in England (although less strict rules were applied in Ireland, allowing Guinness to continue to brew beers closer to pre-war strengths). English breweries continued to brew a range of bottled, and sometimes draught, stouts until the Second World War and beyond, although they were considerably weaker than the pre-war versions. The drinking of porter steadily declined and production ceased in the early 1950s, although a revival of the style began in 1978.