During the Second Northern War, the city was prepared for a defence lasting months, with two new towers being built, the moat deepened and a new wrought iron gate installed.
In 1267, the city was attacked by the Nilfgaardian Army, and with the help of a Nilfgaardian spy sent by Ardal aep Dahy, under the alias Xavier Lemmens, the oil caldrons were rigged, causing a fire in a guard tower. This gave the troops time to enter Rosberg, butcher its residents, and eventually take the city. The troops then choose to torch the city, causing all of Rosberg to burn. However, nonhumans were blamed for the fires, thus several pogroms started in the country.