Jonas Kęsgaila

[2] Jonas Kęsgaila was Elder of Samogitia (1449–1485), castellan of Trakai (1477) and Vilnius (1478–1485).

[2] Jonas was a powerful magnate in Samogitia and even conducted independent foreign policy with the Teutonic Knights.

[3] During the Thirteen Years' War (1454–1466), the Samogitians attacked the Knights, including their stronghold in Klaipėda (Memel) in 1455.

[4] The Samogitian border was closed, disrupting communication between the Teutonic Knights in Prussia and its branch in Livonia.

These actions are usually interpreted as direct support to Casimir IV Jagiellon, King of Poland.