The advent of industrialism brought with it a significant amount of social changes in London from the mid 1800's and all the way to 1901, when London was considered the richest city in the world.
The most important and significant of these social changes came in the form of a newly-created and quite strong middle class. The London middle classes were made of people whose skills, education, and ability to conduct and create businesses allowed them to earn enough money to lead comfortable and luxurious lifestyles that were comparable, and sometimes more financially liberal, than those of the upper-class aristocrats.
This comes from the fact that the middle classes were able to sustain their lifestyles, for they could find many ways to earn money. Contrastingly, the aristocrats were a dwindling race made of heirs and heiresses of old-money families whose fortunes were becoming less and less formidable.
After all, the increase of the middle class's "new money" was powerful enough to even buy titles and properties from some philandering aristocrats whose money management skills were too poor to keep up with an increasingly demanding new market.
These scenarios comprise the reality of the 1890's society; one in which, for example, a lawyer (who was considered then a "working bee") was able to establish a successful practice and live quite well, complete with his own country estate, and with a fashionable London flat "for the season".
With these newly-formed social groups, came new dynamics. The newly-rich middle classes were able to compete with the aristocrats in terms of fashion, manners, diet, and even daily lifestyles. This is what we witness in the theater of the 1890's particularly in plays such as G.B. Shaw's Pygmalion, as well as with all of Oscar Wilde's plays, particularly The Importance of Being Earnest, Lady Windermere's Fan, and The Ideal Husband.
These plays are representative of the genre of Comedy of Manners. These pieces treat the social topics that were relevant at the time, giving a funny twist to them in that they often exaggerate and mock the behaviors of both the aristocrats and the middle class "nouveau riches"-newly rich.
For this reason, we see a lot of satire and farce in the theater of the 1890's but it is Oscar Wilde's The Importance of Being Earnest which took the genre by the horns and made it unforgettable. In this play we basically see every element of the comedy of manners at its most powerful staging.