 Henry IV Probus, using the support of the powerful German patricians, mastered the capital city at the end of 1288.Bolesław II did not give up however, and aided by support from Władysław, Władysław's brother Casimir II Łęczycki, and perhaps troops from Przemysł II, he attacked branches of the Probus coalition – Henry III of Głogów, Bolko I of Opole, and Przemko of Ścinawa – who were returning to Silesia.On 26 February 1289, a bloody battle occurred on the fields near Siewierz (Przemko of Ścinawa died there), resulting in a great victory for the branches of Mazovia-Kujawy.