Old inhabitants of Barovia from before the time of Strahd von Zarovich. It seems they fell foul of Strahd von Zarovich and their race is rapidly declining.
Petrina was a favourite of Strahd von Zarovich and when her people tried to free her from him she died (was killed?).
Strahd von Zarovich killed every female Dusk Elf and cut the tips of Kasimir Velikov's ears off.