After the death of their father on 21 January 1426 Trojden II and his brothers, not wanting to further weakened their positions and domains with subsequents divisions, decided to co-rule all their paternal inheritance. Another factor could be the difficult relationship with their mother, and after an eventual division of their domains they are forced to give her part of the lands as her dower. Despite the nominal co-rulership of the brothers, they administered separately their parts of the duchy. An analysis of the documents issued by Trojden II showed that he received Płock.M. Wilamowski: Trojden II, [in:] K. Ożóg, S. Szczur (ed.): Piastowie. Leksykon biograficzny, Kraków 1999, p. 318. On 8 September 1426 he and his brothers Siemowit V and Władysław I paid homage to the Polish King at Sandomierz.
