Juan II of Aragon, the Big (Medina del Campo, Castile, June 29 1398 - Barcelona; January 20 of 1479) was duke of Peñafiel, king of Navarrese (1425 - 1479) and king of Aragon, of Sardinia and of Sicily (1458 - 1479), son of Fernando I de Antequera and of Leonor Urraca of Castile, countess of Alburquerque. Juan II were one of the most long-lived king in the XV century.
     From 1415 at 1416 represented his father in the government of Sicily and Sardinia like general lieutenant. Of return to Spain helped his bigger brother, Alfonso V the Magnanimous, in the problems there been in Castile with Álvaro de Luna, valid of his cousin the Castilian king Juan II.
    In 1419 contracted marriage with Blanca of Navarrese daughter of the king Carlos III the Nobleman, and widow of Martin the Youth. To death of Carlos III in 1425, his daughter Blanca and the infant Juan was proclaimed jointly kings of Navarrese. In the Summer of 1429, for favoring the interests of his siblings the Infants of Aragon, Juan invaded Castile for the valley of the Henares. When he will outline battle near Jadraque, the intervention of his sister María, wife of Juan II of Castile, determined the end of the expedition and, to the long one, the loss of that war in the next year.
    Juan lived unaware to the matters of Navarrese, governed by his wife, and he stayed surrendered fully to the Aragonese matters and his interests in Castile. This way, and for helping to his brother the king of Aragon, Alfonso V, participated in the unsuccessful campaign for the conquest of Naples in 1435. That expedition gave cause to a satirical work of the marquis of Santillana: "La comedieta de Ponza" (The little comedy of Ponza). Years later, faced again with his cousin and brother-in-law the king Juan II and with his valid don Álvaro de Luna, he entered in war against Castile. He took Atienza and Torija, but he was defeated in 1445 in the battle of Olmedo, with which started end to the Aragonese influence in the Castilian matters.
     To the death of Blanca de Navarra in 1441, Juan married in the second nuptials (1445) with Juana Enríquez, daughter of Fadrique Enríquez, Admiral of Castile, and political rival of Álvaro de Luna. The sudden political intervention of Juan in Navarre motivated the confrontation between the king and his first-born son Carlos de Viana, fruit of his marriage with the deceased queen Blanca. In effect, Juan broke the testament of his wife and, instead of delivering the Navarrese crown to his son Carlos, who like Viana's prince was the legitimate heir, delivered to him only the possession of the place in the Kingdom. This provoked a strong dissatisfaction in Navarre, which led to the civil war in 1451.
     The malcontent of Carlos de Viana and the more and more serious differences with his father, ended in a civil war between the "Beaumont lineage", Carlos's followers, and the "Agramont lineage" defenders of Juan's cause. Both faced on October 23, 1451 in the battle of Aibar, where Carlos was defeated and made prisoner along with his condestable Luis de Beaumont. Juana Enríquez, in advanced state of gestation, left Estella and moved to Sos (Aragon), where she gave birth to her son Fernando. Decided to that her son was the future king of Aragon, showed all her distaste towards Carlos who once liberated, by request of the Spanish Parliament of Lérida, went to Naples in search of the protection of his uncle Alfonso V.
     In 1454, Juan II, there was named by his brother Alfonso V substitute of Aragon and Catalonia, while this was governing the kingdom from the south of Italy and Sicily. Four years later Alfonso's death took place, who was lacking direct heirs and Juan was successor in the throne of Aragon, although he turned out to be forced to deliver to his son Carlos the government of Catalonia. The Spanish Parliament assembled in Lerida in 1460, asked Juan II to liberate his son and forced him to respect in 1461 the Capitulation of Villafranca del Penedés, where prohibited him to enter in Catalonia without permission and his real authority was limiting himself significantly.
     Carlos dies on September 23, 1461 as a consequence of a pulmonary illness (or poisoning, as it was speculated, indicating his stepmother Juana Enríquez). His death and the nonperformance of the agreed in Villafranca del Penedés unleashed the Catalan civil war, which coincided with the riot of the peasantry, initiated in February, 1462 (meet as the riot of the "payeses de remensa"). The king managed to maintain the loyalty of Aragon, Valencia and Sicily opposite to the riot of Catalonia, where he was considered to be a destitute of the Crown.