Who caused the war of the roses to start?

The War of the Roses was primarily caused by the power struggle between the rival houses of Lancaster and York, both of which claimed the English throne. The conflict began in 1455, fueled by political instability, weak leadership under King Henry VI, and rising tensions among the nobility. The rivalry was exacerbated by issues of inheritance and governance, leading to a series of battles over control of the crown. Ultimately, it was a culmination of longstanding grievances and ambitions that sparked the civil war.