Career
Jonas Kęsgaila was Elder of Samogitia (1449–1485), castellan of Trakai (1477) and Vilnius (1478–1485). During the Thirteen Years" War (1454-1466), the Samogitians attacked the Knights, including their stronghold in Klaipėda (Memel) in 1455. These actions are usually interpreted as direct support to Casimir IV Jagiellon, King of Poland.
However, this might be oversimplification as the attacks were possibly carried out by unruly Samogitians looking for loot, closing of the border was not considered an ac of war, and Lithuanian nobles generally did not support the war.
