The Vallaki Vistani Camp was once a prison community for Dusk Elves after the war. The Vistani were responsible for keeping them in line in the early years after the war. Over generations the relationship between the Dusk Elves and Vistani evolved into that of friendly neighbors.
The few Dusk Elves that survived Strahd's invasion of the valley became prisoners-of-war and allowed only by Strahd's grace to continue living in their traditional homes over the watchful eye of the Vistani. Kasimir, the leader of the Dusk Elves, worked with the Vistani over generations until the two groups became friendly with each other.
When the Sunseekers first arrived at the Vallaki Vistani Camp, they were tasked by Luvash with finding his daughter Arabelle. With Kasimir's help, they rescued her from her kidnapper Bluto over Lake Zarovich. As a token of their appreciation, the Vistani offered the Sunseekers precious metals and hospitality to the party.