[1][2] Daumantas is mentioned in chronicles only once and, in absence of any other evidence, is presumed to be a short-ruled Grand Duke who inherited the title after Traidenis' death in 1281 or 1282.
[3] Seven Russian chronicles record the same brief story that in March[4] or August 1285 Lithuanians, led by Grand Duke Daumantas, attacked the domain of Simeon, Bishop of Tver.
[5] A day before the feast of the Transfiguration of Jesus (August 6), the Lithuanian army was defeated by united forces of Tver, Moscow, Volokolamsk, Torzhok, Dmitrov, Zubtsov, and Rzhev.
[3] These two raids into Russian lands indicated a new direction in Lithuanian interests as Traidenis had concentrated on Livonian Order, Black Ruthenia, and Galicia–Volhynia.
Historians attempted to place the two raids in the context of sibling rivalry in Novgorod between Dmitry and Andrei, sons of Alexander Nevsky, or succession in Tver by fourteen-year-old Mikhail of Tver, but no definite conclusions can be made due to lack of written sources.