Question: What queen's marriage was a condition of the promises in the Poland-Lithuanian union that was threatened to be severed by the Lithuanian Civil War?
Sentence (from "Lithuanian Civil War (1432–38)"): The Lithuanian Civil War of 1432–1438 was a conflict over the succession to the throne of the Grand Duchy of Lithuania, after Vytautas the Great died in 1430 without leaving an heir.
Relevant evidence: No