Eldest brother, king Alfonso V, left the Iberian Peninsula around 1430, leaving his wife, Maria of Castile, (1401–1458), the sister of king John II of Castile, and his meddling and impulsive brother, John, later king John II of Aragon, to live in Naples, Italy, doing military expeditions to conquer "manu militari" former fiefs of the Aragonese Crown and leading a sexual life there without bothering at all with his Queen, Marie of Castile, king John II of Castile's sister and having in Naples bastard royal children with a few women from the Italian nobility did not help either.
There was a loyal but ambitious, albeit modest Castilian nobleman, a bastard from Aragonese nobility stock, known as Álvaro de Luna who helped king John II of Castile to fight hard and many times successfully against his scourging cousins, males and females, in 1423.
To be brief, Alvaro let it be known López Dávalos negotiations with the Muslim subjects of the vassal Kingdom of Granada, quite near of the Murcia territories held by the Constable, whether they were real or just a political concoctions, to become thus the undisputed protector of the young king of Castile and getting rid of the close involvement of López Dávalos with the Aragonese cousins of the king.
The trick worked and Rui López Dávalos had to go into the Kingdom of Aragon, dying with the weight of a discredited life between 1423 and 1428.
Hernando Dávalos made part of the well documented Toledo "Comuneros" fighting against the extra tax contributions, circa 1518, asked for by king Charles I of Spain (Holy Roman Emperor Charles V) to bend the wishes of the German Electors in his wishes of becoming a Holy Roman Emperor.
His properties in Toledo were seized and sold publicly to pay for the military efforts trying to make them obedient to 18-year-old king Charles, born in Ghent, Flanders, an aspiring, and successful, Holy Roman Emperor.
Constable of Castile
Álvaro de Luna
, (circa 1388 - publicly executed,
Valladolid
, 3 July 1453). From a painting by
Sancho de Zamora
, circa 1430, at the Álvaro de Luna chapel in the
Cathedral of Toledo
. Idolized by king
John II of Castile
since he was around 15 and he was a bastard, aged 27, he was most ambitious for social recognition and status, chasing out
Constable of Castile
Ruy López Dávalos, (1357-1428) around 1423. He was a Master of the Military
Order of Santiago
too, a much treasured position by Infante Henry of Aragon, who had died of wounds in Calatayud as a consequence of the
Battle of Olmedo
on 19 May 1445, fought on behalf of his master the King. It is said, further, that on 19 February 1445, Queen Consort of Portugal, Leonor and her sister Maria, Queen Consort of Castile, seem to have died of the same symptoms, then diagnosed by some people as poisoning. The king of Castile, who married then young, capricious, disequilibrated,
Isabella of Portugal
, a noble family Portuguese lady in waiting only then, better known as the mother of famous and mighty Queen
Isabella I of Castile
could not stand Alvaro arrogance and protective behavior towards her husband king John II of Castile. The killing of one of the Queen's secretaries, Perez del Vivero, attributed to Álvaro, meant his death sentence at Valladolid courts of law, 1453. King John II of Castile, is said to have died, brokenhearted by missing his devoted 64-year-old friend since he was 27, on 20 July 1454, aged only 49, nurtured by Álvaro since he was 15 and bullied for ever around by his hard royal Aragonese cousins. Queen Isabel I of Castile mother and one of the ruling Queen of Castile's daughters, Queen
Joanna of Castile
's son, king
Charles I of Spain
, a.k.a.
Holy Roman Emperor
Charles V
, respectively, because of their severe inherited madness