You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "Vaidotas was a son of what ruler of medieval Lithuania who was the Duke of Trakai?" whose answer is Kęstutis.
Each document should contain about 30 words, and these documents should contain useful information.

Query: Vaidotas son of ruler of medieval Lithuania Duke of Trakai
Useful Output:

Doc 1: This chapter aims to reveal the image of Vytautas as expressed by the Duke himself and propagated by his entourage. The image is perceived as
Doc 2: Kęstutis was grand duke of Lithuania from 1381, when he ousted his grandson Jogaila, to 1382, when he was in turn deposed by Jogaila.
Doc 3: Vytautas was born about 1350, probably in Trakai, the oldest son of Kestutis. He first achieved prominence as an ally of his father in the
Doc 4: Vytautas the Great, Grand Duke of Lithuania, Duke of Trakai, Postulated King of Hussites, was born circa 1350 in Senieji Trakai, Lithuania to Kęstutis
Doc 5: Kęstutis (; – 3 or 15 August 1382) was a ruler of medieval Lithuania. He was the Duke of Trakai and governed the Grand Duchy of Lithuania