After heavy fights on 12 and 13 September, fought in the area of Błonie, Ołtarzew and Ożarów, the regiment crossed the Kampinos Forest and reached the Modlin Fortress. There, the regiment took part in defence of that area until the capitulation of the fortress on 29 September.
Following intense battles on 12 and 13 September, fought in the Błonie, Ołtarzew, and Ożarów region, the regiment traversed the Kampinos Forest and arrived at the Modlin Fortress. There, the regiment participated in defending that area until the fortress's surrender on 29 September.