The history of pubs can be traced back to Roman taverns, through the Anglo-Saxon alehouse to the development of the modern tied house system in the 19th century.
How far back does the history of pubs go back? What was the Anglo-Saxon pup called?  What is a pub tied to in the 19th century? What Roman businesses were analogous to modern day pubs? What similar establishments existed in the Anglo-Saxon world? In what century did the tied house system develop?