The Prussians besieged many castles that the Knights had built and could not send large armies to fight in the west. Prussians were not familiar with Western European siege tactics and machinery and relied on siege forts, built around the castle, to cut the supplies to the garrisons. The Teutonic Knights could not raise large armies to deliver supplies to the starving garrisons and smaller castles began to fall.
The Prussians surrounded numerous fortresses constructed by the Knights, which they were unable to send large armies to engage in battles in the west. The Prussians lacked familiarity with Western European siege tactics and machinery, instead relying on fortified strongholds surrounding the castles to sever supplies to the besieged garrisons. As a result, the Teutonic Knights were unable to assemble large forces to deliver sustenance to the famished garrisons, leading to the downfall of smaller fortresses.