Philip of Castile, Lord of Cabrera and Ribera
Philip of Castile (Seville, 28 May 1292 – Madrid, April 1327), was an "infante of Castile", son of Sancho IV of Castile and María de Molina.
He was Lord of Cabrera and Ribera and regent of his nephew Alfonso XI of Castile.
He married his cousin Margarita de la Cerda, daughter of Alfonso de la Cerda.
Fadrique Alfonso, Lord of Haro
Fadrique Alfonso of Castile, 1st Señor de Haro( 1334 –1358), 25th Master of the Order of Santiago( 1342 – 1358), was the fifth illegitimate child of Alfonso XI of Castile and Eleanor of Guzman.
He was born in Seville.
Tello Alfonso, Lord of Aguilar de Campoo
Tello Alfonso of Castile (1337 – October 1370) was the seventh of the ten illegitimate children of Alfonso XI of Castile and Eleanor of Guzman.
He was a prince of Castile and First Lord of Aguilar de Campoo.
In Spanish he is known as "Tello de Castilla, Infante de Castilla; Señor de Aguilar de Campoo, de Vizcaya, de Castañeda y de Lara".
Eleanor de Guzmán
Eleanor de Guzmán(" Leonor")( 1310 – 1351) was a Castilian noblewoman and long- term mistress to Alfonso XI of Castile.
She was the mother of King Henry II of Castile.
Constance of Portugal
Constance of Portugal (
pt:
"Constança"; 3 January 1290 – Sahagún, 18 November 1313), was Queen of Castile by her marriage to Ferdinand IV.
She was the eldest child and only daughter of King Denis of Portugal and his wife Elizabeth of Aragon, later Saint.
Juan Núñez III de Lara
Juan III
Núñez de
Lara y de la Cerda( born Juan Fdez.
de la Cerda y Núñez de Lara:
1313- Burgos, 28 November 1350), Lord of Lara and Vizcaya, son of Ferdinand de la Cerda( 1275 – 1322) and Juana Núñez de Lara" the Little Dove".
Despite belonging to the House de la Cerda and aspiring to the Castilian- Leonese throne during the reigns of Sancho IV of Castile, Ferdinand IV of Castile and Alfonso XI of Castile, he carried the family name of his mother which corresponded to the name of his lordship.
He was Lord of Biscay by his marriage to Maria Diaz de Haro II, daughter of Don Juan de Haro" the Eye".
He was also Lord of Villafranca, Oropesa, Torrelobatón, Lerma, Paredes de Nava, Castroverde and Aguilar.
Ensign of the King and Lord Steward of Alfonso XI of Castile.
He was a great- grandson of Alfonso X the Wise, King of Castile and León, and Louis IX, King of France.
Juan de Castilla y Haro
Juan de Castilla y Haro, most commonly known as Juan el Tuerto( the one- eyed)( b.?- d. 31 October 1326, Toro), was a Spanish noble of the House of Haro and of the royal line of the Kingdom of Castile descended from Alfonso X of Castile.
He was the Lord of Cuéllar from 1319 to 1325 and the Lord of Biscay from 1322 until his assassination by order of King Alfonso XI of Castile in 1326.
Alfonso XI of Castile
Alfonso XI of Castile (13 August 131126 March 1350), called the Avenger ("el Justiciero"), was the king of Castile, León and Galicia.
He was the son of Ferdinand IV of Castile and his wife Constance of Portugal.
Upon his father's death in 1312, several disputes ensued over who would hold regency, which were resolved in 1313.
Once Alfonso was declared adult in 1325, he began a reign that would serve to strengthen royal power.
His achievements include solving the problems of the Gibraltar Strait and the conquest of Algeciras.
María de Molina
María Alfonso Téllez de Meneses( c. 1265 – 1321), known as María de Molina, was queen consort of Castile and León from 1284 to 1295 by marriage to Sancho IV of Castile, and served as regent for her minor son Ferdinand IV( 1295- c.1301) and later her grandson Alfonso XI of Castile( 1312- 1321).
Alfonso de la Cerda
Alfonso de la Cerda, (Valladolid 1270 - Ávila 1333), called the disinherited, was the elder son of Ferdinand de la Cerda and his wife Blanche of France, and was a grandson of Alfonso X of Castile.
Alfonso and his brother Fernando were candidates for the Castilian-Leonese crown during the reigns of Sancho IV of Castile, Ferdinand IV of Castile and Alfonso XI of Castile.
In 1331, Alfonso renounced his rights and swore allegiance to Alfonso XI of Castile.

Question: Who is the maternal grandmother of Alfonso Xi Of Castile?
Answer: Elizabeth of Aragon