Imperial Stout
One of the darkest beer styles available which are usually quite strong, ranging from 8-12% in ABV. This style originally stems from the 1800s when beer was made in the UK and then shipped to the Imperial Court of Russia (hence Imperial Stout!). Today this style has become quite popular especially with US brewers; from experimenting with different ingredients and barrel-ageing. The use of the word 'Imperial' now sometimes refers to beers being big and bold in style — Imperial IPAs, etc.