Mild is one of, if not the, oldest beer styles in the country. Until the 15th century, ale and mead were the major British brews, both made without hops. Once hops were introduced, the gravity of ale was reduced, as hops replaced a strong brew in order to preserve the ale. Milds continue to use a minimal amount of hops to produce a stronger tasting beer.

Usually dark brown in colour, due to the use of well-roasted malts or barley, milds are less hopped than bitters and often have a chocolatey character with nutty and burnt flavours. The darkness comes from darker malts and roasted barley which are used to compensate for the loss of hop character. However, not all milds are dark. In Scotland, the 60 /- is similar to a light mild. Milds today tend to have a ABV of 3% to 3.5%.