Francesco Sforza sometimes asked his young daughter to act as an intermediary between him and his mother, so that she could help him to return to the graces of Bianca Maria, during the times when he and his wife entered into a quarrel for some reason.

[...] she hated vices with anguish and especially of shameless women [...] she knew with great modesty with each generation to behave, objecting to the flatterers, mischievous and evils-takers, whom she escaped as a pestiferous diseaseOn 10 October 1465 she married the Duke of Calabria Alfonso of Aragon, son of King Ferrante of Naples.

The bride had already left Milan with the wedding procession, when the marriage risked skipping due to the sudden death of the leader Jacopo Piccinino, son-in-law of Francesco Sforza.

The situation was finally resolved and Ippolita, after staying for two months in Siena and then having passed through Rome, reached Naples on September 14, where with great magnificence she was received by Alfonso her husband and her father-in-law Ferrante, who set up many parties and shows to celebrate the wedding.

In the early days relations with her husband, three years younger than her, had to be good, if in that same year the fifteen-year-old Eleonora of Aragon, in turn about to marry Ippolita's younger brother, Sforza Maria Sforza, desired "even some of the carezone [which] she sees do no time from the Duke of Calabria to the duchess", and if Ippolita herself writes to her mother that she and Alfonso slept together every night and that they often had fun between hunts and tickling in country residences.

[7] If so, then the relations between the spouses had to deteriorate later over time, both for the continuous and brazen betrayals of Alfonso, who would have found a new and complacent lover in Trogia Gazzella, and for the bad character that distinguished him.

In fact, already a few weeks after the wedding we have news of the first jealousies of Ippolita towards her spouse: Alfonso is described by ladies and ambassadors as a very beautiful young man, "so pretty you couldn't tell", but "so much alive that he could not sit still for half an hour".

[8] Even Alfonso, however, was jealous of his wife: in the summer of 1466 he did not want Ippolita to play with Giovanna Sanseverino anymore when she went to visit her accompanied by her relative Gian Francesco.

[8] Starting from December 1466 some letters from both the ambassadors and the person directly concerned report an episode of jealousy on the part of Ippolita, at that time pregnant with the firstborn, who had commissioned her own servant, Donato, to stalk her husband wherever he went.

[8] Alfonso's violent reaction should not be surprising: he was not by chance hated by the Neapolitan people for having offended his subjects with "cruel insults et iniurie", for having been guilty of the most nefarious crimes, such as "violar virgine, taking for his dilecto the women of others" and for practicing the "vitio detestando et abominevole de la sodomia", he was therefore only beginning to manifest his real character to his wife.

She also formed excellent friendships with her brother-in-law Federico, like her lover of letters and a man with a very sensitive soul, who very often went to visit her in Castel Capuano or in the villa called della Duchesca staying in his company.

However, the visit turned out to be very short, as Ippolita, at the time in the midst of her beauty as a woman, was forced to return quickly to Naples to escape, it seems, the flattery of her brother, who showed very ambiguous feelings towards her.

[12] Her family members were always close to her, including the king and queen, and so also the eldest son Ferrandino who, initially very far from home, as soon as he received news of his mother's illness immediately returned to comfort her, being the favorite child of Ippolita.

[12] Great funeral preparations were made and the deceased, dressed in white brocade, with a golden circle on her head and jewels and rings on her fingers, was buried in the church of the Annunziata in Naples.

[12] While her husband risked his life in Otranto, fighting for the liberation of the city from the Turks, Ippolita spent the nights kneeling in prayer in front of the altar; once she stayed there nine consecutive hours, other times six or seven, depending on the need she felt at that moment, and her knees were wounded to the bone.

[12] These facts are all told to us by Fra' Bernardino da Rende, who often celebrated Masses for her, while Giovanni Sabadino degli Arienti even tells of miraculous events: it happened one day that her son Ferrandino, at the time about twenty years old, "for grandeza et prestantia de animo, tormenting a gallant horse, that falls on them, so that he was raised believing himself dead spindle".

[12] As for almsgiving, every day she gave more than thirty poor people meat, bread and wine, and increased them to another nineteen on the eve of the Immaculate Conception and on all the feasts of her Protector.

Every evening she anointed the foreheads of her children with holy oil, drawing the sign of the cross, and blessed them with love before sending them to bed, then repeated the same operation in the morning.