Juan Ramón Folch de Cardona y Ximenez de Arenós, (9 January 1418 – 1485), 4th Count of Cardona, Viceroy of Sicily, 1477–1479 was the son of Juan Ramon Folch de Cardona y Aragón, (14 June 1400 – 1st Viscount of Vilamur, 1404, at the age of 4 - 1471), 3rd Count of Cardona, Admiral of Aragon since 22 May 1423 by Lieutenant of Aragon and Queen in charge of Aragonese–Catalan affairs on behalf of her absent husband Alfonso V of Aragon, who resided at Naples, Italy, and Juana Gonzalva Ximenez de Arenós, Countess of Prades, Lady of the Barony of Entenza, sister of the Margerida de Prades who married the ailing and old king Martin I of Aragon.
In 1430 he commanded a fleet of 22 galleys and 8 big ships who assisted besieged Aragonese king in Naples, Alfonso V of Aragon, (1395 - king of Aragon and Sicily 1416 - king of Naples "manu militari" after around 1434 - 1458) taking the French City of Marseille while returning home. He was awarded by Alfonso V of Aragon brother, king John II of Aragon, ( - king successor 1458 - 1479) the Sicilian town of Termes, in 1463, while king John II was at Tudela, kingdom of Navarre, where he disputed, battling, to his son Charles of Viana the Navarrese throne, illegally, in spite of being a widower of Queen Blanca I of Navarre,(1385–1441), only.
King John II, battling against his own Catalan subjects, in rebellion, got extreme difficulties circa 1467, but in 1468, the later king since 1479, John II of Aragon younger son, 16 years old Ferdinand II of Aragon, received the military help of this 3rd Count of Cardona who died in 1471.
Juan Ramon Folch de Cardona y Ximenez de Arenós married in 1445, Juana de Urgel y Aragón, daughter of the Jaime de Urgel, also styled Jaime, Count of Urgel and Royal Princess Isabella of Aragon (1380–1424), a daughter of king Peter IV of Aragon , a widow of the Count of Foix fighting successfully in 1473 against the French troops in the Ampurdan area and the battle of Besós.
When his father, the 3rd Count of Cardona died in 1471, he inherited the title of Admiral of Aragon.
In 1474 he took part in a mission to arrange peace and truces with king Louis XII of France, (1462–1515).
In 1477 he was sent as a Viceroy of Sicily where he stayed till 1479. He died in 1485.
The next Admiral of Aragon would be his 39 years old son, 5th Count of Cardona and Count of Prades, Juan Ramon Folch de Cardona y Urgel but only till 28 September 1486, whereby king Ferdinand II of Aragon and Queen Isabel I of Castile granted the title to his little son Ferdinand.
As the 5th Count was married since 1467 to Aldonza Enriquez, sister of Juana Enriquez, mother of king Ferdinand II of Aragon and both sisters came from the Enriquez family, hereditary Admirals of Castile since about 1404, this decision is easy to understand.
The hereditary title of Admirals of Castile, disappeared in 1711 when the Duke of Medinaceli of the time died in prison in Pamplona Castle. Yet, the title of Admirals of Aragon continued through different families by inheritances, the Palafox family for instance using such title at the beginnings of the 19th Century.
A palace in Granada, now used as a Faculty of Architecture and former Military Hospital, is still named "La Casa del Almirante", "the House of the Admiral", on account of some 17th Century Mendoza family people living there.