Question: Vaidotas was a son of what ruler of medieval Lithuania who was the Duke of Trakai?
Sentence (from "Petras Jonaitis Mantigirdaitis"): Grandson of Petras Mantigirdaitis, he first appeared in written sources in 1476 and reached his career high in 1490s when he was Voivode of Trakai (1490–97) and Grand Marshal of Lithuania (1491–97).
Relevant evidence: No