Konrad II of Masovia

Konrad II is mentioned for the first time in 1262, when Lithuanian Grand Duke Treniota launched a major campaign against Masovia.

He and his father stayed at a small fort in Jazdów when they were surprised by the attack; Siemowit I was killed during the battle and Konrad II was captured by the Lithuanians.

Two years later, the same coalition attacked Władysław Opolski who during the general confusion for the Bohemian-Hungarian war, tried to obtain the Seniorate from Bolesław V, but without results.

The civil war in Masovia prevented Konrad II to claim the Seniorate, but he was allowed to make extensive contacts with the oppositors of the new Duke of Kraków and Sandomierz.

This time (in a different way that in 1279) Konrad II -who was just in Ruthenia with his ally and maternal relative[2] Vladimir III Ivan Vasilkovich, Prince of Volhynia- reacted quickly, and with the help of Vladimir III invaded Lesser Poland; however, he had to face the pretensions of another candidates for the throne: Henryk IV Probus and his own brother Bolesław II.

The exact terms of the treaty are unknown, but is assumed that in exchange of giving his support to his youngest brother for the throne of Kraków, Konrad II obtained his acceptance to the territorial division made in 1275 and also acquired Sandomierz.