In 1430, after the death of Vytautas, Mykolas Kęsgaila and his brothers Rumbaudas and Jaunius Valimantaitis supported the accession of Švitrigaila to the Lithuanian throne. He signed the Treaty of Skirsnemunė of 1431 – the alliance of Švitrigaila with the Teutonic Order during the Lithuanian Civil War (1432–1438). After Sigismund Kęstutaitis seized power, Mykolas and his brothers were imprisoned. Rumbaudas and Jaunius were executed, while Mykolas managed to restore his power and domains.[5] Possibly, such an outcome was influenced by Mykolas' daughter, the wife of Sigismund's influential ally Jonas Goštautas.[5] Mykolas witnessed the Union of Grodno of 1432 between Sigismund and Jagiełło, King of Poland.[2]
According to the Bychowiec Chronicle, after the murder of Sigismund in 1440, Mykolas was among supporters of Casimir IV Jagiellon for the throne of Grand Duke.[6] For such support, he was reinstated as Elder of Samogitia, but the Samogitians did not want to recognize Casimir's authority. As a compromise, Casimir granted a privilege affirming the semi-autonomic status of the region and granting new freedoms to the nobles. Mykolas was able to return to the office.[6]
Notes
^Mykolas (Michael) is his Christian given name, Kęsgaila is his pagan given name, and Valimantaitis is his patronymic used as last name. His sons used Kęsgaila as their last name.
^ abcJonas Zinkus; et al., eds. (1985–1988). "Kęsgailos". Tarybų Lietuvos enciklopedija (in Lithuanian). Vol. II. Vilnius: Vyriausioji enciklopedijų redakcija. p. 298. LCCN86232954.
^Petrauskas, Rimvydas (2003). Lietuvos diduomenė XIV a. pabaigoje – XV a. (in Lithuanian). Aidai. p. 250. ISBN9955-445-67-X.