Ten years later he joined his elder brother Henry III in the Battle of Stolec (24 April 1277) which culminated in a disastrous defeat.

One possible reason for this switch was pressure from Duke Henry IV Probus of Wrocław, who preferred to have the more trustful Przemko in the neighboring realm.

Their good relations were broken in 1296, when Konrad II, after knowing of the involvement of Henry III in Great Poland affairs, joined the military expedition against him led by Bolko I the Strict; however, Bolko I made an agreement with Henry III in Zwanowicach, by which was compelled to give up the towns of Lubin and Wińsko to Konrad II.

However, the Duke of Żagań never reached his new lands in Friuli; after having been stopped in the middle of the road in Vienna due to the lack of approval from pope Boniface VIII, he returned to his country.

However, the knighthood of Żagań, Bolko I the Strict, and Bishop of Wrocław - who even declared the excommunication of Henry III and the interdict over Głogów - intervened in his favour.