Chains: an Explanation
Once the question of pub owners was simple: most pubs were owned by breweries which exercised pretty close control over them (including, obviously, the products sold) whether they were run by a manager (a brewery employee) or a tenant (self-employed). The only important alternative was the free house, where one person or a small partnership was responsible for all aspects of the building and the business. The takeover era, which climaxed in the 1960s and 1970s, didn't disturb this picture - pubs simply ended up in fewer and fewer hands. Generally when one company took over another they closed the brewery and kept all the pubs (closures aside).
In the last decade of the twentieth century all this changed quite suddenly. Traditional free houses - mostly village inns - have been decimated by closures. But the real endangered species is the traditional tied house. This has been happening in two ways. Brewing companies - mostly big ones - have been selling off pubs. Also, brewing companies - of all sizes - have been quitting brewing while keeping their pubs.
The demise of the tied house has been paralleled by the rise of the pub chain - a name used to denote a company which owns several pubs but no brewery. Pub chains, in truth, are not really a new phenomenon: it is their size and importance which is new. Some owe their origins to one man's vision of what pubs ought to be, which he proceeds to realise. Some, as you will probably have realised, are former brewing companies which have held onto their pubs. A purely 1990s phenomenon was a company set up, in effect, by a big brewer to act as a vehicle to dispose of their unwanted pubs to.
However they may have arisen, pub chains seem even more prone to being taken over than breweries. There has also been a boom in wheeler-dealing with pubs being sold from one owner or another. Sadly, sitting tenants are hardly ever offered the freehold on their pubs: the norm is for a big block of pubs to be offered for sale. The result is that it is often very difficult to keep up with who owns what. There may therefore be inaccuracies in the "Owner" column in the database, which we would be glad to hear about.
The long lease is another development of the last ten years or so. These differ from a traditional tenancy mainly in that it is for a fixed term (usually ten or twenty years) and the lessee is responsible for the upkeep of the building. In theory, someone could build up a successful business and have several years to enjoy the rewards before a rent-hike or eviction: more likely, a lessee could go bust in a couple of years and still find themselves liable for several years of rent and repairs. This is sufficiently unattractive that the only lessee that many chains have found for many a pub is another pub-chain.
There's another complication mainly affecting the "superpubs" which certain chains specialise in - they are not actually owned by the chains themselves but by property companies which of course lease them to the chain concerned. In all these cases where there are extra layers between the freeholder and the public, we have listed the company which seems to exercise the main control over what goes on in the pub.
Extensive information on brewing companies and pub chains can be found in the Good Beer Guide. The list of chains supplements this with facts that are either too local, too new or too obscure to be included.