The Erzsebet Clan used to be the succubus clan of the five pureblood clans that ruled Crepuscule. The clan organised, for hundreds of years, a festival known as Walpurgis Night. During the last festival, about 200 years ago, Crawford Erzsebet had a rampage that caused the annihilation of all of the Erzebet clan. No one knows what was the cause for this rampage. The only survivor, Angela Erzsebet, slept for nearly 200 years in order to recover from her injuries. With the Erzsebet clan's demise, their territory was ultimately annexed by Nergal.
Since officially Carmilla is presumed to be dead, Angela Erzsebet and Bathory Erzsebet II were the only surviving members of the clan for the last 100 years. But, with Angela's death, Bathory, who is already very old, is considered the last of the bloodline.