Situation of Lower Prussia during the Thirteen Years' War Anti-Teutonic uprising in Lower Prussia in 1454 The success of the anti-Teutonic uprising led by the Prussian Confederation in the
Chełmno Land in February 1454 created an atmosphere of decisive rebellion against the authority of Grand Master Ludwig von Erlichshausen throughout the Teutonic state. Following the cities of
Pomesania and
Pomerania, the majority of the cities in Lower Prussia also declared disobedience to the Grand Master, and the insurgents began capturing Teutonic castles. The Teutonic garrison in the fortress of Kaliningrad repelled several assaults, but after the destruction of four towers and a significant section of the walls, they surrendered the castle to the insurgents led by the mayor of the Old Town (Altstadt) of Kaliningrad, Andreas Brunau. The fall of Kaliningrad led to the spontaneous defection of Lower Prussia and Samland to the side of the Prussian Confederation: faced with the scale of the rebellion and the helplessness of the besieged Grand Master in
Malbork, the Lower Prussian Teutonic Knights, without attempting defense, fled to Malbork or to Germany. After the Prussian Confederation presented an act of surrender to the crown of the Kingdom of Poland, Kaliningrad pledged allegiance to King
Casimir IV Jagiellon on 19 June 1454, delivered by Chancellor .
Lower Prussia on the sidelines of the main activities of the Thirteen Years' War on the right bank of the Pregolya branch. The fortress was captured and partially destroyed in the early weeks of the anti-Teutonic uprising in 1454, and Kaliningrad was one of the four cities where the Prussian Confederation pledged feudal allegiance to Casimir IV Jagiellon. The situation of the Teutonic Order was changed by the defeat of King Casimir IV of Poland in the
Battle of Chojnice on 18 September 1454. As a result of the battle, the Teutonic army, composed of mercenaries and coming from the west to relieve Malbork, gained open access to the Teutonic state, and the siege of Malbork was lifted. At the same time, the prestigious defeat of Casimir IV was a shock to a significant portion of the towns and gentry of Prussia and Pomerania, who were unconvinced about the new authority. The attitude of the inhabitants of Prussia was also influenced by the undermining of the act of incorporation among the countries of Europe as a result of the Teutonic Order's victory at Chojnice. Exploiting their wavering, the Teutonic Knights recaptured key positions along the
Vistula waterway in 1454 – Sztum, Gniew, and Tczew – threatening to blockade Prussian trade and cut off
Gdańsk from Polish support, although Gdańsk itself managed to repel the Teutonic attack on the city. In October 1454, Grand Master von Erlichshausen reached an
agreement with the mercenaries to defer the payment of their wages, allowing the Teutonic Order to continue its military operations. The recapture of control over the northern part of the Chełmno Land, Pomesania, and parts of Upper Prussia, as well as the occupation of the local fortresses, resulted in the Teutonic Knights creating a barrier securing Malbork and the
Vistula Fens from the south. Based on this barrier, the Order repelled a Polish offensive on Malbork in January 1455, launched by the forces of the Lesser Poland
pospolite ruszenie. Subsequent towns and fortresses, fearing Teutonic reprisals for the previous anti-Teutonic uprising or due to the increase in pro-Teutonic sympathies among the inhabitants, once again switched sides to the Order, while only those fortresses in Pomerania that received sufficient military support remained faithful to the king and the Prussian Confederation. In order to provide this support, the mercenaries still in the king's service were divided into small units and directed to individual fortresses. As a result of these actions, the Teutonic attempts to recapture
Toruń and
Chełmno ended in failure, but repelling the Grand Master's expedition and suppressing pro-Teutonic conspiracies required the deployment of all available Polish forces, which were lacking in other regions. as Teutonic mercenaries from Gdańsk and Tczew began attacking the confederate navigation on the Vistula and constructing fortifications to block the waterway in February 1455. Consequently, the continuation of vigorous defensive actions by the Polish side to maintain possession and unlock the waterway along the Vistula required the acquisition of new financial resources. The imposition of new taxes occurred at the assembly of estates in
Elbląg in February 1455. Opposition from the commoners against the decisions led to an open revolt on 24 March 1455, in two out of three districts of Kaliningrad: the commoners overthrew the council of the Old Town district and seized the arsenal and city gates. After gaining support from the small
Löbenicht district, the bridges connecting both districts with the port district of Kneiphof were destroyed, leading to armed clashes between factions. Mayor Brunau fled to Elbląg. The news of the anti-Prussian uprising in Kaliningrad prompted Grand Master von Erlichshausen to act quickly: on 7 April 1455, Teutonic forces, numbering 2000 men and led by Commander
von Plauen, set out from Malbork towards Upper Prussia, plundering the New Town of
Braniewo and forcing it to swear allegiance to
Ushakovo. Upon receiving news of the Teutonic raid, the Old Town broke off its agreements with the Confederation, and the
Prussian estates adopted a wait-and-see attitude. The Teutonic authorities guaranteed the residents of Kaliningrad that their city and properties would not be subject to pledges for the debts of the Teutonic mercenaries, and that additional taxes imposed by the Prussian Confederation would be lifted. On these terms, the Old Town and Löbenicht swore allegiance to the Teutonic Order on 16 April 1455. The authority of the Order was also recognized by Bishop Nicholas of Samland, and Commander von Plauen occupied the fortresses of
Primorsk and
Löchstadt on the northern shore of the Vistula Lagoon, which lay within Samland. == Plans of both sides ==