The Lasombra traced their origin to an Antediluvian named Laza Omri Bara, and claim to have jointly hunted him down and killed him sometime shortly before the Renaissance. Since neither he nor anyone else convincingly claiming to be the Lasombra Primogenitor showed up for Gehenna, few doubt this claim. The Lasombra were one of the founding clans of the Sabbat, and are basically play the same role in the Sabbat that the Ventrue play in the Camarilla. Their roots in Southern Europe and their tendency during the Dark Ages to hide out in corrupted Catholic Monasteries do much to explaint the Sabbat's love of stolen Catholic symbolism when it comes to titles and hierarchical organization.
The Lasombra are generally known to be excellent politicians, schemers, leaders, and plotters. They alone live up to the old stories of Vampires who do not cast reflections in mirrors, and additionally neither cast shadows nor can be seen by any form of camera or electronic sensor. They instead often have great power over shadows, a power known as Obtenebration, which they can use to hide themselves or others, and even teleport from one shadow to another or use shadows as weapons to impart physical blows to their enemies. Despite a reputation for extreme vanity, they are usually far more willing to control things entirely from the shadows and work through others as puppets, rather than demanding the prestige, respect, and recognition of wielding power openly themselves. However, their affinity for shadows also means that they are even more vulnerable to sunlight and fire than other Vampires, and their pale skins often show scarring not unlike extreme sunburn from an unlifetime's accumulated low-level damge from even candlelight.