The included territories each contributed distinct characteristics to the duchy; for instance, Acquaviva delle Fonti is recognized for its agricultural output,[1] while Ostuni is noted for its historical architecture.

[2] Historically, the Duchy of Bari reflects the complex cultural interactions in southern Italy, influenced by various ruling powers such as the Byzantine Empire, Norman conquerors, and Spanish authorities.

In addition to its political and economic roles, the duchy played a part in the cultural development of the area, fostering artistic and architectural advancements that are acknowledged in studies of Italian history.

In Apulia, the dispute saw the prince of Taranto Giovanni Antonio Orsini Del Balzo on the side of the Aragonese and the mercenary captain Giacomo Caldora appointed by the Angevins as feudal lord of Bari and Bitonto.

[4] Giacomo Caldora laid siege to Modugno in late August 1436, with his son-in-law Count of Avellino Troiano Caracciolo, but was unsuccessful and contented himself with ravaging olive and almond groves in the surrounding countryside.

[5][6] Clashes and retaliation between the towns that sided with the two factions ended only when Alfonso of Aragon succeeded in seizing the throne of Naples in 1442 with the help of Filippo Maria Visconti.

Alfonso of Aragon reconfirmed to the loyal prince of Taranto all the possessions he had won in the struggles that had just ended: Modugno was the fief of Gian Antonio Orsini and remained there for thirteen years, hated by the population for his tyrannical actions.

Orsini and the Duke of Milan Francesco Sforza also supported the Aragonese monarch during the Conspiracy of the Barons who wanted the return of the Angevins (at this time, the House of Valois-Anjou.

[9] Upon the death of the prince of Taranto Gian Antonio Orsini, which occurred on 13 November 1463, in Altamura, his possessions, including Modugno, returned to the state property, that is, to the king of Naples.

[11] On 19 June 1464, King Ferdinand I of Naples offered Francesco Sforza the duchy of Bari and the two towns of Modugno and Palo del Colle, in place of the lands of the prince of Rossano, promised as a reward for his support in suppressing the conspiracy of the barons.

[12] Ferdinand I on 9 September 1464 issued the privilege of donation in which he stated that he had always considered “Sforza Maria Sforza among his dearest people and always loved and considered him as a son on a par with Eleonora, promised to him in his betrothal, both because of the bond of kinship and because of his singular character and the innumerable benefits received from his father Francesco [... ] He therefore gladly gives in perpetuity to him and to his legitimate heirs and successors of both sexes the city of Bari and the lands of Palo and Modugno with their castles, hamlets, men, vassals, vassals' incomes, feuds, feudatories, subfeudatories, customs, rights of the customs and any other right arising from the useful dominion, with the houses, estates, olive groves, vineyards, gardens, etc., with the court of justice for the recognition of civil cases and the other rights, jurisdictions, accounts, etc., pertaining by custom and law or otherwise to the said lands, and with the title of duchy..., agrees that Sforza Maria Sforza and his successors shall bear the title of duke of Bari in all deeds and writings, and shall enjoy the favors, liberties and honors of barons and dukes.

"[13] Before taking possession of the duchy, the Sforzas asked their representative in the kingdom of Naples, Antonio da Trezzo,[14] to prepare a report regarding the economic situation and tax revenues of the new fiefdom of Bari, Modugno and Palo del Colle.

[19] Ludovico il Moro never went to his own duchy, which was administered by governors: in 1482 it was governed by Benedetto Castiglioni,[20] two years later by his sister Ippolita, wife of Alfonso II.

The Aragonese army, commanded by the young Ferdinand, entered Romagna at a time when Charles VIII of France was welcomed by Ludovico il Moro, who had called him to his own aid.

Charles VIII entered Naples on 22 February 1495, and sent Macedonio Paduano, in his time governor of Bari, to occupy the duchy and the Calabrian territories on behalf of Moro.

Upon the death of his beloved wife Beatrice d'Este in 1497, Ludovico (by then Duke of Milan) renounced the entire duchy in favor of their second son Sforza Francesco, who was still an infant.

[26] Later Ludovico il Moro moved to the side opposed to the French by allying himself with the Republic of Venice, the state of the Church, Ferdinand the Catholic, and the Emperor of Austria.

Ludovico il Moro, before fleeing to Emperor Maximilian of Austria to prevent Isabella of Aragon's son Francesco from being elected duke in his absence, tried to take him with him to Germany.

He sent one of his relatives, Alessandro Pagano, to take possession of the territories in southern Italy, but Ludovico's officials refused to hand over the powers having received directives to cede the lands exclusively to Isabella.

Ludovico entered Milan on 5 February 1500, and Frederick of Naples was forced – in the wake of these successes – to recognize Moro's possession of territories in Apulia and Calabria, to the detriment of his niece Isabella.

When the French occupied nearby Bitonto they had to decide whether to lay siege to Bari, but they renounced it deeming it "ignoble and very shameful for strong men (to fight) a female".

She favored public education by getting each convent to entrust two friars with the task of teaching the populace; she granted facilities to teachers such as increased salaries, exemption from allowances and free housing.

[38] Public works created in Bari by Isabella of Aragon include the rebuilding of the pier, the renovation of the castle (later modifications replaced elements introduced by the duchess) and the project to surround the city with a canal to improve its defense.

[39][40] Isabella is blamed for her oppressive fiscal policy promoted by her minister Giosuè De Ruggiero (who, moreover, managed to buy the fiefdom of Binetto in 1511 and who was kicked out when the duchess died).

The harassment continued even when Gian Antonio De Ruggiero became bishop of Ostuni in 1517 (in 1507 Isabella of Aragon had taken possession of that city's fiefdom in place of the two Calabrian towns of Burello and Rosarno) and retained the benefices of the Modugnese churches.

[42] The people, exasperated, wrote a letter in 1527 to Duchess Bona, who succeeded her mother Isabella, denouncing the situation in very harsh tones,[43] and, subsequently, they demanded that no other archpriest be elected who was not from Modugno.

When you receive this, we ask you to order all the priests of our country to celebrate the Mass of the Holy Spirit every Monday, beginning with the first one that comes next, and to pray to our Lord God to make us content with what we desire.

(your majesty).”[56] After the death of her husband resulting in the accession to the throne of her son Sigismund Augustus, the proud Bona Sforza began to ponder her return to Italy.

Modugno passed into the hands of the Spanish crown but, as Philip II needed money, he sold the fief in 1558 to the viceroy of Sicily Don Garcia de Toledo for 44,000 ducats.

To counteract the great power concentrated in the hands of the feudal lords, the government of the Spanish viceroyalty of Naples intervened with a twofold strategy: fragment the large estates and sell the small fiefdoms separately; and encourage the release from serfdom of the enfeoffed towns, which, by paying a fee, could acquire state freedom by depending directly on the king's authority.