The upper class is a social group, comprising those privileged or superior to others in some respect. Criteria for distinguishing an upper class can be economic, racial, religious and cultural. Although the term upper class gained prominence along with the development of sociology and political sciences, the roots of this idea can be found much earlier. The idea of social stratification, a class system, can be seen in the works of ancient Greek philosophers, like Aristotle (384-322 BCE), in The Bible, as well as in the basic social and religious texts of the Indians and the Chinese.
Aristotle wrote of aristocrats as the upper class, those people which are (literally) the best. Ancient Rome exhibited explicit social stratification. In the early years of Rome, the upper class consisted of patricians, who controlled the religious and political offices of the city. The remainder of the population were the plebeians. Later on, when the monarchy was abolished (509 BCE) and Rome became a republic, the upper class consisted of senators.
Once a patrician was elected a senator, that meant a secure occupation for life. Senators had prestige, influence, which distinguished them as a separate, higher class. This influence was retained even after the gap between the plebeians and the upper class was partially bridged following the Conflict of Orders - the first class conflict documented in history. The resolution to the conflict granted a raft of rights to the plebeians and opened the way for the emergence of nobility. This was the upper class within the plebeian strata.
Classes existed not only in politics, but also in the daily life of the Romans through the patrons and the clients. Patrons were those who were wealthier, more educated and more powerful than clients and thus constituted the upper class in daily business. Clients went to their patrons in search of advice, assistance, or protection. In return, the client had to respond to the patron's commands. The patronage was passed from generation to generation. It was a sound system, although not legally binding.
In feudal Europe, prior to the 17th century, the upper class comprised the large landowners, or lords, while peasants, or non-land-owning farmers, constituted the lower strata. Merchants and tradesman, by virtue of their greater income, better housing and general wealth, will have been regarded as middle class.
The growth of industry and the capitalist economic systems by the 19th century led to the emergence wealthy commercial and industrial capitalists. In a class conscious society such as England at that time, while this group owned the capital, ran the banks, the mills, mines and the factories, and the working class depended on them for work and their income, these nouveau riche were rarely regarded as upper class. Some, through patronage, works of charity or the whim of the monarchy at the time, may have been ennobled and therefore joined the upper class, or the Establishment. Otherwise they would be termed upper middle class. In Britain, money could not buy class; to be upper class would require "breeding," and long-term status.
It was this situation that provoked German philosopher Karl Marx (1818-1883) to develop his theory of the class conflict. According to Marx, the upper class was formed by those who had control over the means of economic production and distribution, as well as over the capital for investment. The role of the upper class, he wrote, was to exploit the lower class by giving it poor pay, imposing long working hours and forcing it to work in unsafe conditions. Marx forecast that the differences between the social classes were so great that they would ultimately lead to a conflict. German sociologist Max Weber (1864-1920) elaborated the concept of a social group, arguing that it is not defined solely by economic criteria but also by status and power.
In Europe, in the half-century following the end of World War I in 1918, the boundaries between the classes began to blur. Titled, upper class families, sometimes referred to as "old money," often found that they no longer had the means to maintain the lifestyle, country estates and homes that they had enjoyed for centuries previously. "New money," from the middle classes and politicians, began to acquire their property and influence.
In the 21st century, social class prejudices remain. These prejudices are especially robust in societies where the stratification was enforced for centuries. In India, for example, some people still disapprove of marriages between members of different castes.