Katherine of Valois (1401-1437), also known as Catherine of France, was the youngest daughter of the mad King Charles VI of France. When England's King Henry V conquered Normandy and northern France, it was agreed by the Treaty of Troyes (1420) that he would marry Katherine and become the heir of Charles VI. The next year, Katherine bore the future King Henry VI (who, however, seems to have inherited her father's genes for madness; he went insane in the 1450s and was deposed in 1461). Henry V died in 1422, and Katherine married, or perhaps merely slept with, the Welshman Owain Tudor; their grandson became King Henry VII. But Katherine was long dead by then, having been ignored by almost everyone for fifteen years.