Question: Petras Jonaitis Mantigirdaitis, was a prominent noble of the Grand Duchy of Lithuania. in 494, Mantigirdaitis was sent on the diplomatic mission to negotiate peace with the Grand Duchy of Moscow and marriage of Helena of Moscow to where?
Sentence (from "Stanisław Kiszka"): Shortly before his death, Kiszka also became Grand Marshal of Lithuania.
Relevant evidence: No