Question: Who is Sancho De La Cerda, 1St Marquis Of La Laguna's paternal grandfather?

Knowledge 1: Sancho de la Cerda, 1st Marquis of la Laguna
Sancho de la Cerda, 1st Marquis of la Laguna, (in full), (c. 1550 – 14 November 1626) was a Spanish nobleman and diplomat.Sancho was the third son of Don Juan de la Cerda, 4th Duke of Medinaceli and of his wifeDoña Joana Manuel de Portugal.He joined the royal household, and rose to become Spanish Ambassador to Flanders, member of the council of state and of the council of war under King Philip III and later head of the household of his wife, Queen Margaret of Austria.He was rewarded with the title of "Marquis of la Laguna de Camero Viejo" on 16 February 1599. [SEP] Knowledge 2: Juan de la Cerda, 4th Duke of Medinaceli
Juan de la Cerda, 4th Duke of Medinaceli (c. 1514 – 1575), Grandee of Spain, was a Spanish nobleman.He was the son of Don Juan de la Cerda, 2nd Duke of Medinaceli, by second wife María de Silva.In 1552 Juan de la Cerda inherited the titles from his older half-brother Gastón de la Cerda y Portugal.Both half brothers, the 3rd, Gaston, and the 4th Duke, Juan II, are widely reported in many places and articles as being born "out of marriage" from different women and being "legitimated" males by the Crown as legal successors to their father, the second duke Juan I, also, apparently, a legitimated bastard, however.In 1557, King Philip II of Spain appointed him Viceroy of Sicily, a position he held until 1564.During that time he besieged with a fleet the North-African harbor of Tripoli, now in Libya, dealing with Dragut, a Turkish privateer and Ottoman admiral.The force, including ships from Spain, Genoa, Tuscany, the Knights of Malta and the Papal States, was however nearly destroyed in the Battle of Djerba.In 1567 he was appointed Viceroy of Navarre supposedly staying there till 1572, but it seems that towards the end of 1570, he became head of the household of Queen Anna of Austria, position he held until his death in 1575.In the spring of 1572 Philip II sent Medinaceli to the Netherlands as governor.According to Henry Kamen, Medinaceli reported to the king that "“Excessive rigour, the misconduct of some officers and soldiers, and the Tenth Penny, are the cause of all the ills, and not heresy or rebellion.”"One of the governor’s officers reported that in the Netherlands "“the name of the house of Alba”" was held in abhorrence.Medinaceli lobbied the King for the removal of the Duke of Alba as military commander.Deciding that the views of Medinaceli and Alba were not compatible, Philip II removed both and replaced them with Requesens.
Knowledge 1: Sancho de la Cerda, 1st Marquis of la Laguna
Sancho de la Cerda, 1st Marquis of la Laguna, (in full), (c. 1550 – 14 November 1626) was a Spanish nobleman and diplomat.Sancho was the third son of Don Juan de la Cerda, 4th Duke of Medinaceli and of his wifeDoña Joana Manuel de Portugal.He joined the royal household, and rose to become Spanish Ambassador to Flanders, member of the council of state and of the council of war under King Philip III and later head of the household of his wife, Queen Margaret of Austria.He was rewarded with the title of "Marquis of la Laguna de Camero Viejo" on 16 February 1599. [SEP] Knowledge 2: Juan de la Cerda, 5th Duke of Medinaceli
Juan de la Cerda, 5th Duke of Medinaceli( 1544 – 29 May 1594), Grandee of Spain,( in full), was a Spanish nobleman and Ambassador in Portugal.He was the son of Don Juan de la Cerda, 4th Duke of Medinaceli and of Joana Manuel, daughter of Sancho de Noronha, 2nd Count of Faro.In 1565 he married Donna Isabella d’ Aragona, daughter of Don Antonio d’ Aragona, 2nd Duke of Montalto with whom he had two children.In 1580, he married for a second time, with Juana de la Lama, 4th Marchioness of la Adrada, a widow since 1571 of Don Gabriel de la Cueva, 5th Duke of Alburquerque, deceased as a Governor of the Duchy of Milan, Italy, with whom he had two more children.
Knowledge 1: Sancho de la Cerda, 1st Marquis of la Laguna
Sancho de la Cerda, 1st Marquis of la Laguna, (in full), (c. 1550 – 14 November 1626) was a Spanish nobleman and diplomat.Sancho was the third son of Don Juan de la Cerda, 4th Duke of Medinaceli and of his wifeDoña Joana Manuel de Portugal.He joined the royal household, and rose to become Spanish Ambassador to Flanders, member of the council of state and of the council of war under King Philip III and later head of the household of his wife, Queen Margaret of Austria.He was rewarded with the title of "Marquis of la Laguna de Camero Viejo" on 16 February 1599. [SEP] Knowledge 2: 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.

Answer: Juan de la Cerda, 2nd Duke of Medinaceli