The Assamites trace their ancestry to Haqim, the captain of the guard in the City of Enoch before the flood. Training his first childer to be the police and judges of that first city, their duties inevitably led to their becoming quite adept at tracking down and killing fellow vampires. These opportunities for gaining power through Diablerie eventually drove the clan somewhat mad, and they became obsessed with blood, diablerie, and killing, even by vampiric standards. Spreading out through the Mideast and into Europe, they made their fortress at Alamut a byword for assassination, intrigue, and murder. Hated by almost all other clans for their habit of killing high-ranking vampires regardless of clan, they are nonetheless tolerated as an outer clan of the Camarilla because it is just so gosh-darned convenient to have access to an entire clan of blood-mad but incredibly effective hired blades when you need them. Joining the Camarilla as an outer clan surprisingly early, they became the most feared assassins in history. However, gaining the protection and support of the Camarilla came at a price: the Tremere blighted them with a Blood Curse, which made them unable to take the power of another vampire through Diablerie, or for their power to be passed to another vampire in that way. Still, the Assamites became so loyal to the Camarilla that many of the Assamite Antitribu who had joined the Sabbat and became the core of the Black Hand were in actuality sleeper agents, who during Gehenna would defect back to the Camarilla and bring the rest of the Black Hand with them.
When Haqim rose from his Torpor at Gehenna, he initially joined with Ventrue and Arikel to lead the Camarilla, but he unsuccessfully tried to betray and kill them, falling instead into a trap and being burned to death in sunlight. Many of the Black Hand Assamites fled to rejoin the Sabbat after this, but the clan itself supposedly remains part of the Camarilla.
As assassins by nature and choice, the Assamite powers tend to revolve around sneakiness and speed, with the unique abilities to weaponize their own blood, either as poison or as a corrosive acid-like substance. Many of the clan embraced Islam or Christianity in an attempt to control their own violent impulses, with mixed success. Older Assamites from before the Tremere cursed the clan probably diablerized many vampires in their youth, and thus could have the powers and abilities of almost any other clan in addition to their own.