In the broadest sense, every privileged landowner could be called a boyar; in a narrower sense, the term refers to a senior member of a prince's retinue during the tenth through thirteenth centuries, and marked the highest court rank during the fourteenth to seventeenth centuries. The word boyar probably stems from a Turkic word meaning "rich" or "distinguished." Coming from a mixed social and ethnic background, boyars served a prince, but they had the right to change their master, and enjoyed full authority over their private lands.
The relationship between a prince and his boyars varied across the regions. In the twelfth to fifteenth centuries, boyars acquired considerable political power in some principalities ruled by members of the Ryurikid dynasty and in Novgorod, where they formed the governing elite. In the Moscow and Tver principalities, boyars acknowledged the sovereignty of the prince and cultivated hereditary service relations with him. In the sixteenth and seventeenth centuries, the rank of boyar became the highest rung in the Muscovite court hierarchy. It was reserved for members of elite families and was linked with responsible political, military, and administrative appointments.
During the seventeenth century, the rank of boyar became open to more courtiers, due to the growing size of the court, and it gradually disappeared under Peter the Great. It is often assumed that all boyars were members of the tsar's council, the so-called Boyar Duma, and thereby directed the political process. This assumption led some historians to assume that Muscovy was a boyar oligarchy, where boyars as a social group effectively ran the state. However, there was always a hierarchy among the boyars: A few boyars were close advisors to the tsar, while most acted as highranking servitors of the sovereign.
See also: boyar duma; muscovy; okolnichy
Poe, Marshall T. (2003). The Russian Elite in the Seventeenth Century. 2 vols. Helsinki: Finnish Academy of Science and Letters.