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Europe

European nobility originated in the feudal/seignorial system that arose in Europe during the Middle Ages. Originally, knights or nobles were mounted warriors who swore allegiance to their sovereign and promised to fight for him in exchange for an allocation of land (usually together with serfs living thereon). During the period known as the Military Revolution, nobles gradually lost their role in raising and commanding private armies, as many nations created cohesive national armies.

This was coupled with a loss of the socio-economic power of the nobility, owing to the economic changes of the Renaissance and the growing economic importance of the merchant classes, which increased still further during the Industrial Revolution. In countries where the nobility was the dominant class, the bourgeoisie gradually grew in power; a rich city merchant came to be more influential than a nobleman, and the latter sometimes sought inter-marriage with families of the former to maintain their noble lifestyles.

However, in many countries at this time, the nobility retained substantial political importance and social influence: for instance, the United Kingdom's government was dominated by the (unusually small) nobility until the middle of the 19th century. Thereafter the powers of the nobility were progressively reduced by legislation. However, until 1999, all hereditary peers were entitled to sit and vote in the House of Lords. Since then, only 92 of them have this entitlement, of whom 90 are elected by the hereditary peers as a whole to represent the peerage.

The countries with the highest proportion of nobles were Polish–Lithuanian Commonwealth (15% of an 18th-century population of 800,000), Castile (probably 10%), Spain (722,000 in 1768 which was 7–8% of the entire population) and other countries with lower percentages, such as Russia in 1760 with 500,000–600,000 nobles (2–3% of the entire population), and pre-revolutionary France where there were no more than 300,000 prior to 1789, which was 1% of the population (although some scholars believe this figure is an overestimate). In 1718 Sweden had between 10,000 and 15,000 nobles, which was 0.5% of the population. In Germany it was 0.01%.

In the Kingdom of Hungary nobles made up 5% of the population. All the nobles in 18th-century Europe numbered perhaps 3–4 million out of a total of 170–190 million inhabitants. By contrast, in 1707, when England and Scotland united into Great Britain, there were only 168 English peers, and 154 Scottish ones, though their immediate families were recognised as noble.

Apart from the hierarchy of noble titles, in England rising through baron, viscount, earl, and marquess to duke, many countries had categories at the top or bottom of the nobility. The gentry, relatively small landowners with perhaps one or two villages, were mostly noble in most countries, for example the Polish landed gentry. At the top, Poland had a far smaller class of "magnates", who were hugely rich and politically powerful. In other countries the small groups of Spanish Grandee or Peer of France had great prestige but little additional power.