Golden Bull of Rimini

[6] Backed by his Polish cousins Leszek I the White and Henry I the Bearded, he initially was successful, but was eventually confronted with relentless Prussian counter attacks and incursions across the borders into his Masovian lands.

This Imperial authorisation was signed by a large number of princes, such as the Archbishops of Magdeburg, Ravenna, Tyre, Palermo and Reggio, the Bishops of Bologna, Rimini, Cesena, Mantua and Tortosa, the Dukes of Saxony and Spoleto, and the Margrave of Montferrat.

[16][17] Duke Konrad actually had no intention of ceding the Chełmno Land and initially supported bishop Christian of Oliva establishing the Order of Dobrzyń (Fratres Militiae Christi).

[18] On 16 June 1230, the Treaty of Kruszwica was supposedly signed, according to which Duke Konrad ceded the lands of Chełmno as well as all other conquests in Prussia to the Teutonic Knights, represented by Grand Master Hermann von Salza.

[19][20] In 1234, Pope Gregory IX issued the Golden Bull of Rieti (Pietati proximum), that presents the written authorization of all previous verbal consent given in August and September 1230 after the Treaty of Kruszwica and confirms all prior agreements.