Alfonso X, King of Castile & Leon (el Sabio) was born on November 23, 1221, in Toledo, or Burgos, the son of Fernando III, King of Castile, and Beatrice von Hohenstaufen.

He married Violante de Aragon (1), who was born in 1236, on November 26, 1248, in Valladolid, and they had eleven children, Berenguela, Beatriz, Fernando de la Cerda, Leonor, Sancho, Constanza, Pedro, Juan, Isabel, Violante, and Jaime. Alfonso also had four illegitimate children, Beatriz, Fernández, Urraca, and Martin, with Mayor Guillende Guzman.

Alfonso became king in 1252. He had many scholars in his travelling court, and he was an active participant in their writing and editing. Some were experts on Roman law, which Alfonso hoped to make the basis of a uniform code for his lands. The court, gifts to friends, and foreign intrigue proved expensive, and Alfonso taxed heavily.

He crushed a Muslim revolt in 1252, and a revolt by nobles in 1254. Morocco, Granada, and Murcia invaded in 1264, but Alfonso won with Aragonese help, and annexed Murcia. In 1272, a revolt, and withdrawal to Granada, by nobles forced him to confirm local privileges.
Alfonso claimed many foreign titles, notably that of Holy Roman Emperor. In 1257, bribes won him four electoral votes for emperor to three for Richard of Cornwall, but Alfonso was unable to claim his reward due, in part, to opposition from the Pope. In 1275 Richard died, and Alfonso went to France to appeal to Pope Gregory X, who persuaded him to renounce his claim.

Under Alfonso's patronage the schools of Seville, Murcia, and Salamanca were furthered, and Muslim and Jewish culture flowed intoWestern Europe. He was largely responsible for the Siete Partidas, a compilation of the legal knowledge of his time; for the Alfonsine tables in astronomy; and for other scientific and historical works.

In his later years, Alfonso's ill health rendered him progressively less able to carry out his duties and caused him to act arbitrarily, and in 1282, an assembly of nobles, prelates, and townsmen transferred the responsibilities of government from the king to his second son, Sancho, ignoring the claims of Alfonso's grandson, also Alfonso, who as the son of Alfonso's oldest son, was legitimately heir to the throne. For two years, Castile was torn apart by civil war, between the followers of Sancho and the young Alfonso, until the king's death in 1284, when Sancho became King Sancho IV.

Alfonso died in 1284, in Seville. Violante died in 1301, in Roncevalles.
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Children of Alfonso X, King of Castile & Leon, and Violante de Aragón(1):

i Fernando de la Cerda (1) [17th great grandfather of Perucho]

ii Sancho IV, King of Castile & Leon (el Bravo) was born on May 12, 1258. He married, in July 1281, in Toledo, Maria Alfonsa de Molina, the daughter of Alfonso de Molina and Mayor Alfonsa de Meneses.

In 1275, Morocco and Granada invaded Castile, and Ferdinand de la Cerda, Alfonso's oldest son and heir to the throne, was killed in the fighting. A dispute over the succession between the supporters of Fernando de la Cerda's son, Alfonso, and the king's second son, Sancho, ensued. By the King's own code of laws, the claims of the son were undoubted, but the Cortes decided in favor of the brother, Sancho, who was proclaimed heir to the throne, while the young princes were taken to Aragon by their grandmother Violante de Aragón.

Alfonso X's ill health rendered him progressively less able to carry out his duties and in 1282, an assembly of nobles, prelates, and townsmen transferred the responsibilities of government from the king to Sancho. When the king died in 1284, Sancho became King Sancho IV.
Sancho and Maria had seven children, Isabel de Limoges, Fernando IV King of Castile & León, Alfonso of Castile, Enrique of Castile, Felipe de Cabrera, and Beatrix of Castile. Maria died after 1260, in Valladolid, and Sancho died on April 25, 1295, in Toledo.

iii Berenguela de Castilla was born before December 6, 1253, in Seville. She was a nun and died in about 1313, in Guadalajara.

iv Beatriz de Castilla (2) was born in December 1254, and married William of Montferrat, IX Lord of Montferrat. Beatriz died after1280. He died in 1292.

v Leonor de Castilla (2) was born in about 1256 and died in 1275.

vi Constanza de Castilla was born in about 1259.

vii Pedro de Castilla, Señor de Ledesma, was born before June 1261, and married Marguerite of Narbonne in 1281, in Burgos. They had a son, Sancho de Ledesma. Pedro died on October 20, 1283, in Ledesma.

viii Juan de Castilla was born before April, 1264. He married Joanna of Montferrat and was killed el la Vega de Granada on June 25, 1319. In 1292, Sancho IV King of Castile, brother of this Juan de Castilla, captured the town of Tarifa from the Moors, and placed control of the town in the hands of Alonso Perez de Guzman. In 1294, Juan de Castilla in an act of treason aganst the Crown of Castile, offered to help the Moslem King Mohamed recover Tarifa. What happened then is told in the biography of Alonso Perez de Guzman.

ix Isabel de Castilla was born in about 1265, and died young.

x Violante de Castilla (2) was born in about 1266.

xi Jaime de Castilla, Señor de los Cameros, was born before August 11, 1268, and died on August 9, 1284.
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Children of Alfonso X, King of Castile & Leon, and Mayor Guillén de Guzman:

xii Beatriz de Castilla (1) was born in 1242. In 1253, she married Alfonso III, King of Portugal. They had eight children, Fernando, Denis King of Portugal, Affonso de Portugal, Vicente de Portugal, Branca of Lorvano, Sancha, Maria, and Costanza. Beatriz died on October 27, 1303.

Of these children, Denis, King of Portugal, married Isabel de Aragon (2), and Affonso de Portugal married Violante de Castilla (1).

xiii Alfonso de Castilla died in 1281.

xiv Urraca de Castilla

xv Martin de Castilla