Unknown Description of the Border between Mazovia and the Teutonic Order. Part II: the Military District of Balgij (the Court Districts of Pisz and Elk)

The second part of the article deals with heretofore unknown descriptions of the southern border of the court district of Pisz, part of the military district of Balgij (temporarily Rynsk), which started on the river Boleszówka, a tributary of the Turosl (Rudna) and then ran eastward along the Kolno Upland. This fragment of the frontier between Mazovia and the Teutonic Order, all the way to the headspring of the Biebrza, was also established in the course of negotiations conducted in Bratian in 1343, and followed the northern edge of the Upland. Meanwhile, in the descriptions under examination we encounter a boundary delineated across the centre of the Upland, from the mouth of the Korczowoda (Labna) to the Pisa, crossing the Losiowa Biel marshes and then along the Skroda, the Chojna and the Wissa, up to the mouth of the Biebrza, which corresponded approximately to the territorial claims made by the Order during the 1330s and 1340s. Some of the examined descriptions remain undated. The first, most probably written by Jan von Sayn, the military commander of Balgij, originates from 1405-1407, and in May 1412 found itself among documents whose purpose was to assist an Order mission setting off for negotiations with the Polish side in Buda. This is the second most important description (after the one contained in a letter by the military commander of Ostróda, 15 February 1413), since it depicts the mechanism of the efforts of the Teutonic Knights aimed at a legal appropriation of a considerable part of the Mazovian territory. The preparation of the document was probably based on three consecutive descriptions, made at the end of the fourteenth century, which are discussed in detail. By publishing unknown descriptions of the boundaries made for the purpose of a Polish-Teutonic Order trial conducted after the battle of Grunwald (or prepared earlier and only used at the court proceedings) the authors wished to supplement heretofore knowledge about the border disputes between Mazovia and the Teutonic Order from the last quarter of the 14th century to the second decade of the 15th century, which up to now have been known only from outdated, frequently 19th century ascertainments made by German and Polish researchers.