The Camarilla came about in an attempt to hold vampire society together against the power of the Inquisition in the 15th century. Under its iron guidance, the Tradition of the Masquerade grew from a cautious suggestion to the guiding principle of Kindred unlife. Even today, the Camarilla concerns itself with the enforcement of the Masquerade, maintaining harmony between Kindred and kine, and battling the Sabbat, which it views as its direct opponent. The Camarilla touts itself as the society of the Kindred, and it is partially correct. It is the largest sect of undead on the planet.
Almost any vampire, regardless of lineage, may claim membership in the Camarilla. In truth, the Camarilla asserts that all vampires are already under its aegis, regardless of the wishes of the vampires in question.
The Camarilla's archenemy is the monstrous sect known as the Sabbat. Perceived as mindless savages and bloodthirsty fiends by the Camarilla and independent clans alike, the Sabbat is vilified among the society of the Damned, and for good reason. They're just not the reasons other Kindred claim. While the "Kindred" of the Camarilla espouse concealing themselves among mortals and maintaining the tattered vestiges of their Humanity, the Sabbat favors a different philosophy.
Since the close of the Middle Ages, the dangerous Tango danced by Camarilla and Sabbat has shaped the face of Kindred society. The bloody conflict has broken millions of human lives and shaped the secret history of cities across the world. Of course, there are some clans that watch both sects leap at one another's throats in the name of the Jyhad - and prefer to have none of that, thank you very much. Although they certainly have the pedigree of true clans (as opposed to the mongrel bloodlines that occasionally surface), the independent clans share a powerful disinclination to "take sides" in the Jyhad. Of course, some of the younger members of each clan can be found in both Camarilla and Sabbat.