What Happened in History: Browse Historical Facts on Kudos 365

John I of Castile marries Beatrice of Portugal in a union arranged to secure Castile's claim to the Portuguese throne. After Beatrice's father, King Ferdinand I of Portugal, died later in 1383, John of Castile attempted to press his wife's claim to the throne. However, this led to a Portuguese period of political turmoil and the Castilian attempt was ultimately repelled by Portuguese forces under John of Aviz, who would become King John I of Portugal.