The ClanDestine is the name given to the family of Adam Destine (an immortal Englishman born in the 1200's), his true love (a magical genie), and their children.
Although not truly on the same plane of existence, Adam's love contacts him periodically, and another member of the Clan soon is born. Apparently, dozens and dozens of individuals have been born over the centuries, each living an extended lifespan due to their heritage. Many would stay at their ancestral home, Ravenscroft Manor in England, living a happy life.
Ultimately, however, their happiness was shattered in recent years, sometime in the 1970's, by one of their own: Vincent Destine. Although his specific deeds remain a mystery, they quickly forced the family to become divided. When Adam felt forced to kill Vincent, his own son (and, some thought, his mother's favorite), some members sided with Adam, and others were directly opposed to his actions. With Vincent dead, Adam fled from Earth entirely, distraught over his actions and the family woes.
Other troubles were coming to a head as well. The world was fast approaching an age where the Destine's family anonymity could be in question. Before, the long-lived and powerful Destines could enjoy moving from place to place without compromising questions or confusing identities. More often than not, the family fell victim time and time again to bigotry and hatred born from fear. Newton Destine proposed the "Relative Strangers Protocol," where the family would separate across the globe, to lessen the chances that anyone would learn the existence of the family.
This kept a period of stability for the family, as each remained in the life he or she created, maintaining limited contact with the rest of the family, until Rory and Pandora’s actions during one night of crime-fighting caused the existence of the family to be discovered. This led to a chain of events that caused the murder of many Destine family members. Most of the family soon banded together in stopping the threat, and afterward they chose to remain closer together now that the Protocol was compromised.