The brewing industry is a global business, consisting of several dominant multinational companies and many thousands of smaller producers ranging from brewpubs to regional breweries. More than 133 billion litres (35 billion gallons) are sold per year—producing total global revenues of $294.5 billion (£147.7 billion) in 2006.
Pubs can be traced back to Roman taverns, through the Anglo-Saxon alehouse to the development of the tied house system in the 19th century. In 1393, King Richard II of England introduced legislation that pubs had to display a sign outdoors to make them easily visible for passing ale tasters who would assess the quality of ale sold.