On 27 July 1144 Salomea of Berg, Duke Bolesław's widow and Włostowic's bitter enemy, died. As in accordance with the Duke's will, her province of Łęczyca had to revert to the Senoriate Province of Władysław, the voivode, in agreement with the Junior Dukes, planned a coup d'état in order to take the contested district, perhaps as emolument for the younger Henry. Again in this case, Władysław appealed for aid to his Kievan allies. Without waiting the arrival of food he sent his troops against the forces of Bolesław IV the Curly and Mieszko III; unexpectedly, Władysław suffered a defeat. It wasn't until the arrival of the Kievans that the fate of the battle and the war turned to Władysław's side. Immediately, a favourable peace treaty was made, which permitted the High Duke to take full control over Łęczyca; however, he had to give to the Kievan cohorts, in exchange for their aid, the Polish castle at Wizna.