It’s not really feasible for me to continue much further without actually discussing the origins of the pub, and the terminology that surrounds their definition.
The use of the word “pub” as we know it largely developed during the 19th century, which isn’t to say that these establishments were new, or that there was no drinking culture predating the Victoria era. Quite to the contrary, in fact. Rather, before this time there was a greater variety of terminology, referring to many different kinds of establishment. “Pub” itself developed from the “public house”, which was but one type of institution (also known as an “ale house”), alongside the earlier coaching inns (which provided accommodation to travellers) and taverns (focused more on wine and food). Some of these survive in name, but very few still retain their original architecture. One such is the famous George Inn (Borough SE1, fig. 6) with its galleries facing a central court.
The 18th century, following changes to licensing laws in 1830, also saw the rise of smaller and far less elaborate establishments with more restrictive licences, called “beer houses”, often no more than a single room or two with a basic frontage — the last remaining beer house to be converted to a fully licensed pub, as recently as 1998, was The Fox and Hounds (Belgravia SW1, fig. 7). To a certain extent these were a reaction to the phenomenal development of the dram shop during this era, trading primarily in spirits (originally brandy, but more and more focused on gin), many of which by the middle of the 18th century had flourished into the rather more grand gin palaces. By the Victorian era, then, “public house” or “pub” were fairly catch-all terms and could be used to refer to any of these establishments.
Prior to the 18th century, the majority of public houses brewed their own beer. As legislation developed and competition grew, and especially during times of economic hardship such as in the mid-19th century, fewer and fewer publicans were brewing their own beer, and independent breweries began to buy up premises and supply their own beer, allowing the publicans to lease the property. By the 20th century, the majority of pubs were owned or run by breweries and these premises (also known as “tied pubs”) were required to supply the products of that brewery.
As such, the concept of the “free house” developed, being a pub not tied to a brewery.1 In theory this means it is independent, ostensibly “free” of the brewery’s influence. However, this terminology often masks the fact that these pubs may still have agreements with breweries to supply a certain proportion of that brewery’s products. Moreover, in the latter part of the century, a great number of pubs began to come under the ownership of pub company conglomerates (PubCos) with no tie to a particular brewery. Such pubs, for example those of the JD Wetherspoon chain, are also often called “free houses”.
A few truly independent pubs do still exist, providing a constantly changing selection of interesting beers (fig. 8), but looking to the name of the pub will often be of no help in identifying them.
Paul Jennings, The Local: A History of the English Pub (Stroud: Tempus, 2007).
 My Flickr set of pubs labelled “free house”.