50 litas coin issued to honour Kestutis, the Grand Duke of Lithuania (From the series The Rulers of Lithuania).
Kęstutis (Lithuanian pronunciation: [kæsˈtuːtɪs]; born ca. 1297, died on August 3 or August 15, 1382 in Kreva) was monarch of medieval Lithuania. He was the Prince of Trakai and governed the Grand Duchy of Lithuania, 1342–82, together with his brother Algirdas (until 1377), and with his nephew Jogaila (until 1381). He ruled over the Lithuanians and Ruthenians.
The name "Kęstutis" is a derivative from the old form of the name Kęstas, which is a shortened version of such Lithuanian names as Kęstaras, Kęstautas (there kęs-ti means to cope). Historic writing sources reflect different Lithuanian pronunciation.