A royal family is the immediate family of a king or queen regnant, and sometimes his or her extended family. The term imperial family appropriately describes the family of an emperor or empress, and the term papal family describes the family of a pope, while the terms baronial family, comital family, ducal family, grand ducal family, or princely family are more appropriate to describe the relatives of a reigning baron, count, duke, grand duke, or prince. However, in common parlance members of any family which reigns by hereditary right are often referred to as royalty or "royals." It is also customary in some circles to refer to the extended relations of a deposed monarch and his or her descendants as a royal family. A dynasty is sometimes referred to as "the House of ...". As of July 2013, there are 26 active sovereign monarchies in the world who rule or reign over 43 countries in all.
A royal family typically includes the spouse of the reigning monarch, surviving spouses of a deceased monarch, the children, grandchildren, brothers, sisters, and paternal cousins of the reigning monarch, as well as their spouses. In some cases, royal family membership may extend to great grandchildren and more distant descendants of a monarch. In certain monarchies where voluntary abdication is the norm, such as the Netherlands, a royal family may also include one or more former monarchs. In certain instances, such as in Canada, the royal family is defined by who holds the styles Majesty and Royal Highness. There is often a distinction between persons of the blood royal and those that marry into the royal family. Under most systems, only persons in the first category are dynasts, that is, potential successors to the throne (unless the member of the latter category is also in line to the throne in their own right, a frequent occurrence in royal families which frequently intermarry). This is not always observed; some monarchies have operated by the principle of jure uxoris.