A dynasty (
US: /) is a sequence of rulers from the same family,
 usually in the context of a
monarchical system, but sometimes also appearing in
republics. The dynastic family or lineage may be known as a "
 which may be
styled as "
comital", etc., depending upon the chief or present title borne by its members.
periodize the histories of many
sovereign states, such as
Ancient Egypt, the
Carolingian Empire and
Imperial China, using a framework of successive dynasties. As such, the term "dynasty" may be used to delimit the
era during which the family reigned and to describe events, trends, and artifacts of that period ("a
Ming-dynasty vase"). The word "dynasty" itself is often dropped from such adjectival references ("a
Until the 19th century, it was taken for granted that a legitimate function of a
monarch was to aggrandize his dynasty: that is, to increase the
territory, wealth, and power of his family members.
 The longest-surviving dynasty in the world is the
Imperial House of Japan, the
Yamato dynasty, whose reign is traditionally dated to 660 BC.
Prior to the 20th century, dynasties throughout the world have traditionally been reckoned
patrilineally, such as under the
Salic law. In nations where it was permitted, succession through a daughter usually established a new dynasty in her husband's ruling house. This has changed in some places in Europe, where
succession law and convention have maintained dynasties
de jure through a female. For example, the
House of Windsor is maintained through the children of Queen
Elizabeth II, similarly with the
monarchy of the Netherlands, whose dynasty remained the
House of Orange-Nassau through three successive queens regnant. The earliest such example among the major European monarchies was in Russia in the 18th century, where the name of the
House of Romanov was maintained through
a non-ruling female.
Some states in Africa (
Balobedu), determined descent
matrilineally, while rulers have at other times adopted the name of their mother's dynasty when coming into her inheritance. Less frequently, a monarchy has alternated or been rotated, in a multidynastic (or polydynastic) system – that is, the most senior living members of parallel dynasties, at any point in time, constitute the line of succession.
The word "dynasty" is sometimes used informally for people who are not rulers but are, for example, members of a family with influence and power in other areas, such as a series of successive owners of a major company. It is also extended to unrelated people, such as major poets of the same school or various rosters of a single sports team.