Nobility. Military and Political Leader, he was the son of Innico II d'Avalos and Laura Sanseverino. In 1521 he obtained the recognition of Grande di Spagna to add to the title of Marquis del Vasto recognized to his father in 1496. He fought alongside his cousin Fernando Francesco d'Avalos in the battle of Pavia in 1525, distinguishing himself in two different phases. Initially, he led the imperial vanguard of 3,000 men, half German lansquenets armed with pikes and half Spanish achibusiers, who wear white shirts to identify themselves in the dark. After taking the castle of Mirabello, he was forced to retire in order not to find himself in an isolated position from the rest of the imperial army. Later, he participated in a critical phase of the battle in which the Spanish tercios defeated the renowned Swiss infantry in the service of France under the command of Robert de la Marck, lord of Fleuranges (now Florange). This success was also achieved thanks to the sortie of the Pavia garrison commanded by Antonio de Leyva who took the French army behind him. In 1525 Charles V granted Alfonso the fief of Castelleone, in whose ownership he was confirmed by Francesco II Sforza in 1531. On 25 August 1526 the d'Avalos was invested with the title of Marquis of Castelnuovo Scrivia. In 1531 he received the title of count of Castellazzo Bormida. He was taken prisoner by Andrea Doria during the siege of Naples in 1528. In the distribution in favor of the nobles who remained loyal to Spain wanted by Charles V in 1529 of the goods confiscated from the pro-French nobility of the kingdom of Naples, Alfonso d'Avalos received several fiefs. By means of the diploma sent by the city of Regensburg on 28 July 1532, the emperor donated the following assets to d'Avalos and his heirs and successors, Montesarchio (with the title of prince), Castelpagano, Cervinara, Rotondi, Airola, Vico of Pantano, Bisaccia, Vitulano Valley, Procida. To these were added, a house located in the Nile square in Naples, the right of purchase due to the royal court on the castles of Colle and Circello, devolved to the royal state property following the rebellion of Giovan Vincenzo Carafa, Marquis of Montesarchio, the land of Pescara with the title of marquis, similarly falling back to the tax authorities due to the crime of felony committed by the city of Chieti, the castle of Baranello located in the province of Molise, previously belonging to the rebel Antonio Sanfelice, the right that belonged to the royal court to buy back the city of Lettere and the hamlets of Angri, Gragnano, Pimonte, Franchi and Positano, devolved to the royal state property due to the rebellion of Carlo de Miroballo, an annual income of 3,600 ducats on the tax rights of the cities and lands previously mentioned. He was governor of Milan from 1538 to 1546. He was probably responsible for the assassination in Pavia of Cesare Fregoso and Antonio Rincon, which took place on 3 July 1541. He commanded the imperial army in Italy during the Italian campaign between 1542 and 1546 , and was defeated by the French in the battle of Ceresole. On June 28, 1543, together with the Emperor Charles V, he visited the Marquis Aloisio Gonzaga at Castel Goffredo and was a guest of his court. It seems that it was on his initiative that the Accademia dei Trasformati was founded in Milan in 1546 to cultivate "the Italian language and poetry".