Alonso de Castro and Ponce de León, Lord of Castroverde was the son of Don Alvaro Perez de Castro, first Count of Arraiolos, first Count of Viana da Foz do Lima and first Constable of Portugal, and of his wife Maria Ponce de Lion. At the same time, he was a grandson, by paternal line, of Pedro Fernández de Castro, "the one of war", lord of the House of Lemos (deceased in 1343) and of the Portuguese lady Doña Aldonça Lorenço de Valadares (born around 1270). Through his maternal line, his grandparents were Pedro Ponce de León, "the old man", Mr. de Marchena and Bailén, and his wife, Mrs. Beatriz de Jérica and Lauria (1305-1372). Therefore, Don Alonso de Castro descended by paternal way, of Real House of Castile, being greatson of Sancho IV, "the Brave", king of Castile and Leon. By maternal route, was direct descendant of Jaime I the conqueror, king of Aragon. They were brothers of Don Alonso de Castro: -don Pedro de Castro "El Tuerto", Lord of Cadaval, who married Doña Leonor Tellez de Meneses, whose descendants gave continuity to the house of Cadaval; -Dena Beatriz de Castro, married to Don Pedro Núñez de Lara, Earl of Mayorga, a marriage that had no offspring; -na Isabel de Castro, married to Don Pedro Enríquez, Count of Lemos, whose descendants gave continuity to the house of Lemos. Nuptials

Don Alonso de Castro, Lord of Castroverde, married Mrs. María Ramírez de Guzmán, daughter of Don Garci Fernández, first Lord of Villagarcía, and his wife, María Ramírez de Guzmán. Offspring

They were children of Don Alonso de Castro and Mrs. María Ramírez de Guzmán: -don García de Castro y Guzmán, who succeeded his father in the manor of Castroverde; He married Doña Mencía de Guzmán, of whom he had no offspring; -don Fernando de Castro y Guzmán, who succeeded his brother García in the manor of Castroverde in 1435, the date of his death. Don Fernando married Doña Juana de Bazán and Bracamonte, a marriage from which Don Carlos, Don Alvaro, Don Alonso and Dona Isabel de Castro y Guzmán, successive heirs of the manor of Castroverde, were born; -Doña Leonor de Castro, married to Mr. Pedro Bermúdez de Montaos "el viejo", a union from which the successors of the house of Montaos come; -neña Inés de Castro y Guzmán, who contracted first nuptials with Don Pedro de Bazán, Lord of Valduerna, subsequently remarrying Don Lope Sánchez de Ulloa, Lord of Ulloa, being the parents of the first Count of Monterrei, Don Sancho de Ulloa, and of at least three other sons, Don Gonzalo, Dona Maria, and Dona Mayor de Ulloa, all of them with children; -naña Juana de Castro y Guzmán, married to Don Rodrigo de Moscoso, Lord of Altamira, whose descendants come from the Counts of Altamira.

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