 He established the Kęsgailos family in Samogitia, where their power rivaled that of the Grand Duke of Lithuania.Mykolas Kęsgaila was the deputy of Ukmergė (1409–1412), Elder of Samogitia (1412–32, 1440–41, and 1443–50), and castellan of Vilnius (1443–1448).He was a father of Jonas Kęsgaila and Mykolas Kęsgaila the Younger.