The earliest pubs seem to have been set up when the Romans invaded. Their "tabernae" dealt in wine initially for their garrison troops. They soon added the
local "ale" to the menu, to increase their customer base and the name corrupted into "tavern".
As ever, even to this day, the over consumption of any alcoholic beverage brought about social problems and as early as the reign of King Edgar (943-975) attempts were made to limit to number of taverns in any one village. It was Edgar who is reputed to have introduced a measure known as a peg which was the amount of ale consumption permitted a person. This is the origin of the phrase "to take a person down a peg".
This early English ale was not hopped. The use of hops did not arrive until the 13th/14th century, when the resulting hopped beverage became known as beer. This beer had became the staple commodity of the pub in the mid 16th century.
Ale and/or beer was not exclusive to pubs. A great number of women brewed ale at home, this was the small ale, a very weak, sometimes badly filtered beverage of anywhere between 0.5% and 2.5% alcohol content. It was then not surprising that some manual labourers might consume 6 litres per day (over 10 pints) since this was much safer and certainly more palatable than the available drinking water. This type of drink still exists in Belgium as "tafelbier", or in Sweden as lättöl ("light beer") where it is actually classed as a soft drink and escapes alcohol taxes and age restrictions. In the UK of course, whatever the alcoholic content, there is tax, albeit a lower rate on the weaker beers
Taverns and alehouses provided food and drink, inns provided accommodation as well. All proliferated along the highways of the time, seeking to comfort the weary traveller. Around 1470 the term public house seems to have been coined and in 1552 an Act was passed requiring these establishments to be licensed. Around the start of the 18th century competition was keen with the accessibility of cheap gin from Holland and brandy from France. Many a front room was turned into a gin palace with a 1 shilling or so licence. The social problems that arose then were eventually controlled by Acts of Parliament in 1736 and 1751 which limited the consumption to about 25 % of the earlier period.
By Edwardian times, the usual pub had evolved into two room affairs, the public bar or tap room and the saloon bar. The former often referred to as "spit and sawdust". The latter usually carpeted and a premium paid on the price of everything. It was rare for a female to be admitted to the public bar, the saloon was where accompanied women drank. Un-accompanied women were viewed with suspicion.
Some larger estblishment also had a "tap", a building usually seperate from the main building, usually at the opposite end of the yard. This provided a facility for local cusomters to partake of refreshment without mixing with the travellers. The White Hart, Golden Lion and Star had such a facility for many years.
Most of the larger establishment also had a small room with an outside door , known as the jug and bottle. This was for off-sales, where folk could bring their own vessels to collect the beer. There were actually two classes of pub licence ( for on sales and off sales) As late as the 1950s some new pubs had to exist with a beer only licence for a probationary period. I remember "Gus" Orton, when the "The Mount" became a pub again in 1952, had no spirits licence attached to his provisional licence. The customary notice above the front door of most pubs read, after the name of the licensee " licensed to sell beer, wine and spirits by on and off sale".
The Licensing Act of 2003 did away with the Courts and Licensing Justices issuing the licence, which power was transferred to the Local Authority and introduce an new system whereby the premises are licensed and the operator/s now have a personal licence.