Treaties of Cölln and Mewe

The Treaties of Cölln and Mewe, concluded in 1454 and 1455, transferred the Neumark (New March) from the Teutonic Order state to the Electorate of Brandenburg. The Teutonic Knights had received the area as a pawn from Brandenburg in 1402, and as a possession in 1429. Financial shortages due to the onset of the Thirteen Years' War (1454–66) forced Ludwig von Erlichshausen, Grand Master of the Teutonic Order, to pawn the Neumark to Frederick II, Elector of Brandenburg, by the Treaty of Cölln on 22 February 1454, and to subsequently sell it by the Treaty of Mewe on 19 September 1455.

In the second half of the 13th century, the Margraviate of Brandenburg had established the Neumark along the lower Warthe (Warta) river. In 1374/1388, the Lords of Wedel transferred their rights on territories around Schivelbein and Falkenburg to the Teutonic Order state, their eastern neighbor.

On September 29 1402, Sigismund of Luxembourg, King of Hungary and Margrave of Brandenburg, who inherited Neumark after the death of his brother John of Görlitz in 1396, pawned the whole of the Neumark to the Teutonic Order. After the First Peace of Thorn (1411), Grand Master (Hochmeister) Heinrich von Plauen intended to pawn the Neumark to the Polish king, and prepared a respective treaty. The noble estates of the Neumark however, on the basis of their privileges, prevented the ratification of the treaty.