Regent and duke of Lithuania (1386–1392), the brother of Jogaila who governed Lithuania when Jogaila became king of Poland, until supplanted by Vytautas.
Skirgaila was the ruler of the Grand Duchy of Lithuania from 1386 to 1392, governing the vast Lithuanian realm on behalf of his brother Jogaila. When Jogaila married the queen of Poland and became King Władysław II Jagiełło, uniting Poland and Lithuania, he left Skirgaila behind as his regent and deputy to rule Lithuania in his name.
But Skirgaila's regency was contested by his ambitious cousin Vytautas, who rose in revolt against him. By the Ostrów Agreement of 1392, Jogaila abandoned Skirgaila and recognised Vytautas as grand duke instead; Skirgaila was compensated with the Kievan lands, where he died in 1397.
Skirgaila was born about 1354, a son of Algirdas, the great pagan grand duke of Lithuania, and a full brother of Jogaila. He was among his brother's closest supporters in the struggles for power within the sprawling Gediminid family, and when Jogaila accepted Christianity and the Polish crown in 1386, he was the natural choice to hold Lithuania together in his absence.
Skirgaila is remembered as a loyal but harsh and unpopular ruler, devoted to his brother Jogaila's interests but lacking the qualities to win the affection of the Lithuanian nobility and the largely Orthodox population of the Ruthenian lands. The sources describe him as capable in war but severe and heavy-drinking, and he failed to conciliate the many factions of the vast and diverse duchy.
His fatal weakness was that he ruled as a deputy, not a sovereign, and could not command the loyalty that a grand duke in his own right might. Against the charismatic and determined Vytautas, Skirgaila's dependence on his absent brother's backing proved no match; when Jogaila judged it politic to change deputies, Skirgaila was simply set aside. He appears as a faithful lieutenant undone by the impossible position of governing a kingdom that was not truly his.
As Jogaila's regent, Skirgaila governed Lithuania and led its armies, but he faced constant challenge from his cousin Vytautas, whose father Kęstutis had been killed in the earlier family struggles and who now claimed his own patrimony. Vytautas allied even with the Teutonic Knights against Skirgaila and Jogaila, ravaging the country in a damaging civil war.
Unable to defeat Vytautas and anxious to end the ruinous conflict, Jogaila came to terms with his cousin. By the Ostrów Agreement of 1392, Vytautas was recognised as the ruler of Lithuania, and Skirgaila was removed from the regency and granted instead the duchy of Kiev and other Ruthenian lands.
Skirgaila ruled his Kievan lands until his death on 11 January 1397, which contemporaries suspected was caused by poison. He was buried at the Monastery of the Caves in Kiev.
Skirgaila is remembered as the loyal brother who held Lithuania for Jogaila in the first years of the Polish-Lithuanian union, only to be displaced by the greater figure of Vytautas. His removal in 1392 marked the emergence of Vytautas as the near-independent ruler of Lithuania, under whom the grand duchy would reach the height of its power, stretching from the Baltic almost to the Black Sea.