In terms of preferment and prestige, power and property, pride and panache, their position was essentially unrivaled.
— David Cannadine, The Decline and Fall of the British Aristocracy, p.25
Up to the start of the 1880s, the British aristocracy was at the height of its glory. Its members were in pretty much every position of power that existed and its influence was unimaginably vast. Generations of careful marrying, combined with a system of inheritance that passed estates intact from father to son, meant that wealth had been accumulated and increased—buildings, works of art, land, jewelry, estates abroad, and, we presume, cold hard cash. Not to mention titles, which of course put their holders right at the top of the social pile, adding that bracing sense of superiority as the cherry on the top of the cake.
It must have been nice to be at the top. Taxation on landowners was pretty low, servants were plentiful, and civilization had advanced just far enough to make life more pleasant than it had ever been but not quite so far as to spoil the countryside. The gap between rich and poor had been enormous for decades, so that if you started out poor you had very little statistical chance of ending up as wealthy as the economic elite, however hard you worked. For the rich that meant fewer social climbers to contend with (until those dratted Americans came along) and the comforting feeling of being part of a cozy club.
But the 1880s are generally considered to mark the start of an era when that power and prestige began to be challenged, and over the next three generations the aristocracy would seriously lose its grip. Wars had a disproportionate effect on a class that, naturally, supplied many of the military leaders, and wars also had to be financed; the aristocracy would lose many of its tax advantages as well as the century drew to a close.
It was still a pretty good life compared to that of most of Britain’s inhabitants, of course. But the gap between the posh and wealthy and the plain and poor gradually narrowed over the next 70 years, reaching its lowest point in around 1950. The first few decades of the 20th century saw many of the huge country houses demolished, converted into use as schools or institutions, or ceded to the nation to be preserved as tourist attractions.