In the books
In the A Song of Ice and Fire novels, Valysar is a vassal town of Volantis. As it is located on the western side of the river, it does not have any fear of the Dothraki or a need to pay them tribute, unlike its sister-city of Selhorys to the north. Valysar is a middling-sized town by the standards of the Free Cities, but would be a small city by Westerosi standards.
- Valysar at A Wiki of Ice and Fire (spoilers from the books)