Dynasty
A dynasty (UK , US ) is a sequence of rulers from the same family, usually in the context of a feudal or monarchical system but sometimes also appearing in elective republics. The dynastic family or lineage may be known as a "house"; this may be styled "royal", "princely", "comital", etc. depending upon the chief or present title borne by its members. Historians consider many sovereign states' histories, such as Ancient Egypt, the Carolingian Empire and Imperial China, within 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 Ming vase").
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.