Wikipedia
Butigeidis (Budikid; ) was the Grand Duke of Lithuania from 1285 to 1291. He is the first known and undisputed member of the Gediminids.
He started his rule when the Livonian Order and the Teutonic Knights were finalizing their conquest of the Baltic tribes. In 1289, leading about 8,000 troops, Butigeidis attacked Sambia. In 1289 the Teutonic Knights built a castle in Tilsit and their raids intensified. Lithuanians were forced to abandon Koklainiai Castle located on the other bank of the river. Butigeidis was the first to build strong castles along the Neman River. The castle system was further developed after his death and helped to resist the raids until the second half of the 14th century.
Butigeidis transferred Vaŭkavysk to Galicia-Volhynia in exchange for peace. He died in 1290 or 1292, and his brother Butvydas (also known as Pukuveras) inherited the crown.