The Hypatian Codex elaborates that Vismantas was killed in 1251–1253 during an attack against Vykintas' castle (often assumed to be in Tverai).
Lithuanian historian Edvardas Gudavičius analyzed toponyms and determined that the Bulaičiai family most likely hailed from the Šiauliai region.
[2] In the 16th-century Preussische Chronik, it is mentioned that Morta was actually from Sweden since at the time it was a common practice for pagan rulers who were seeking the throne to marry Christian brides from foreign countries.
However, historians consider this claim to be untrue, suggesting that German chroniclers only thought so because they could not believe that a Lithuanian pagan could be such a fierce defender of Western Christianity.
The Chronicle paints an image of a capable woman who advised her husband in political affairs and even provides several colorful dialogues between her and Mindaugas.