sentences:  In his testament dated 1378, King Ferdinand I disinherited his half-siblings, the children of Inês de Castro (John, Denis and Beatrice, frequently called "the Infantes Castro"), whom he accused of an attempt to poison him with the help of Diogo Lopes Pacheco.After several failed betrothals, the marriage of the Portuguese king's daughter to John I of Castile was negotiated by Juan Fernández Anderio.Pursuant to the clauses of the marriage contract, both kingdoms would remain separate, Leonor would be regent and the throne would be inherited by the son born to Beatrice and Juan I, who would be educated in Portugal beginning at age three and would assume the throne at age fourteen.