He was named in honor of the King Saint Ladislaus I of Hungary, who was highly venerated by the Angevin Kings Charles I of Hungary and Louis I of Hungary, considered the model of the perfect King, Knight, and Christian man in Central Europe during that time. Ladislaus of Naples became a skilled political and military leader, protector and controller of Pope Innocent VII; however, he earned a bad reputation concerning his personal life. He profited from disorder throughout Italy to greatly expand his kingdom and his power, appropriating much of the Papal States to his own use. Moreover, he murdered many of his enemies.
He was born in Naples, the son of Charles III and Margaret of Durazzo. He spent his early life with his family in the royal court of Naples, and in 1381 he was created Duke of Calabria and heir by Charles III.
He became King of Naples at the age of nine (1386) under his mother's regency. At the time the kingdom saw a rebellion of the barons (fomented by Pope Urban VI), and there was a risk of a French invasion, since in 1385 the pope had assigned the throne to Louis II of Anjou, Count of Provence, then head of the junior Angevin line. Urban VI refused to recognize Ladislaus, and in 1387 called a crusade against him. Margaret and her son at the time controlled not much more than Naples and its neighborhood. After turmoil broke out in the city, they fled to the fortress of Gaeta, while Naples was occupied by an Angevin army led by Otto of Brunswick, widower of Joanna I of Naples, who had named Louis' father as her heir.
In 1389 the new Pope Boniface IX recognized Ladislaus as King of Naples, although he forbade him to unite it with his family lands in Germany and Italy. In Gaeta, he married Costanza Chiaramonte, the daughter of the powerful Sicilian Baron, Manfredi Chiaramonte; but within a few years the wedding was annulled.
In 1390, the archbishop of Arles poisoned Ladislaus, and though he survived, he subsequently stuttered and was forced to take repeated periods of rest. Also in 1390, Louis II invaded Naples, starting a war with Ladislaus lasting nine years. Ladislaus limited Louis' control to the city of Naples and the Terra d'Otranto.
In 1399, while Louis was fighting against the Count of Lecce, Ladislaus regained the city of Naples with the support of several powerful barons of the Kingdom, including Raimondo Del Balzo Orsini. The Angevins then decided to return to Provence. Ladislaus spent the year 1400 subduing Onorato Caetani, count of Fondi, and the last rebellions in Abruzzo and Apulia.
In 1401 Ladislaus married Mary of Lusignan, daughter of the King of Cyprus. She arrived in Naples in 1402.
In the same period, Ladislaus tried to restore Angevin rule in Hungary, where some of the nobles opposed King Sigismund, and where, since 1390, he had a claim to the crown, and also the lordship of Croatia. His father, Charles III of Naples, grew up in Hungary governing Croatia as Viceroy, and eventually became king as Charles II of Hungary.
Ladislaus ordered the painting of a cycle of Saint Ladislaus' legend in the church of Santa Maria dell'Incoronata in Naples between 1403 and 1414. There the Hungarian King is depicted receiving the royal crown, also fighting against the pagans, and receiving the crown of Croatia. (The cult of Saint Ladislaus and other Hungarian Kings was already present in Naples and other Italian regions since the second half of the 13th century, thanks to Mary of Hungary, Queen of Naples, who brought them when she married Charles II of Naples.)
Considering himself as a descendant of the Holy Kings of Hungary, Ladislaus tried many times to obtain the crown of Hungary. He also had himself crowned Duke of Slavonia, a title with no basis. He first negotiated a treaty with the Republic of Venice, ceding the island of Corfu. He thus obtained free passage in the Adriatic Sea and, with the partial support of the Pope, landed at Zadar on 19 July 1403. However, Ladislaus remained inactive, and returned to Apulia; his authority in Dalmatia remained restricted to Zadar and few other lands. The following year, after the death of Boniface IX, he intervened in Rome in support of the Colonna family, two days after the election of the new pope, Innocent VII.
Ladislaus endeavored to consolidate the royal power at the expense of the barons, and brought about the murder of several members of the Sanseverino family for frustrating his ends. In 1405, he went again to Rome. When some nobles offered him the lordship of the city, the Pope responded by deposing him as King of Naples on 18 June 1406. The Pope had incited Raimondo Del Balzo Orsini to rebel, but he died in January 1406. His wife, Mary of Enghien, continued the rebellion and successfully defended Taranto against a two months long siege by Ladislaus in the spring of 1406. She did not surrender even after Ladislaus and the Pope signed a treaty of peace in July, by which Ladislaus became the protector of the Papal States. He moved to Taranto again early in 1407, this time with diplomatic intentions. Since his first wife had died in 1404, Ladislaus solved the matter of Taranto by marrying Mary of Enghien on 23 April 1407.
In 1407, trying to taking advantage of the feebler personality of the new pope, Gregory XII, Ladislaus invaded the Papal States and conquered Ascoli Piceno and Fermo. In 1408, he besieged Ostia to prevent a success of the French party in the schism between Gregory XII and Antipope Benedict XIII. After a short siege, he captured the city by bribing the Papal commander, Paolo Orsini, and entered Rome on 25 April. Later, Perugia also fell into his hands.
In 1409, Ladislaus sold his rights to Dalmatia to Venice for 100,000 ducats. This was part of his attempts to gain allies in the upcoming war against the Republic of Florence, caused by his expansion in central Italy and his alliance with Paolo Guinigi, lord of Lucca, a traditional enemy of the Florentines. Ladislaus invaded Tuscany, capturing Cortona and the island of Elba from Gherardo Appiani. Florence hired the condottiere Braccio da Montone, who defeated Ladislaus, and he was forced to retreat. However, he had not abandoned his aims in northern Italy, and took advantage of the presence of Pope Gregory XII in Gaeta.
Fearing his aims, the Republics of Siena and Florence and the powerful cardinal Baldassarre Cossa allied against him. Antipope Alexander V excommunicated him, and called Louis II of Anjou back to Italy to conquer Naples. Louis arrived in late July 1409 with 1,500 cavalry and was invested with the Neapolitan crown. The allies' troops, under Muzio Attendolo, Braccio da Montone and other condottieri, invaded the Papal lands under Ladislaus' control and moved to Rome; Orsini, left by Ladislaus to protect the city, defected to them with 2,000 men. However, the allies captured only the Vatican and the Trastevere quarter. Cardinal Cossa and Louis left the siege to their condottieri, and moved to northern Italy and Provence in search of further support.
Ladislaus took advantage of an anti-French revolt in Genoa to gain the support of that city (1410). Rome fell on 2 January, and the allies did not score any other notable results. On 16 or 17 May May, Louis' fleet, carrying new troops from Provence, was intercepted and partly destroyed off the Tuscan coast, with the loss of 6,000 men and Louis' treasure (for a value of 600,000 ducats), which fell into the hands of Ladislaus. In the meantime, Alexander had died, being replaced by Cossa himself as John XXIII. John XXIII proclaimed a crusade against Ladislaus and authorised the sale of indulgences to finance it.
The slow pace of the allied army led the Florentines and Sienese to accept peace with Ladislaus, which he bought by renouncing some of his Tuscan conquests. Louis continued the struggle: his army, led by Muzio Attendolo, crushed the Neapolitan army at Roccasecca on 19 May 1411. He was unable to exploit this success, as he could not breach the defensive line that Ladislaus had set up at San Germano. Louis soon returned to Rome and Provence, where he died six years later. In 1412, the situation turned more favorable to Ladislaus: his condottiere Carlo I Malatesta occupied part of the March of Ancona, and, above all, Muzio Attendolo joined Ladislaus. A peace was eventually signed on 14 June 1412, by which the Antipope paid 75,000 florins, invested Ladislaus with the Neapolitan crown and named him as Gonfalonier of the Church. Ladislaus promised in turn to abandon the cause of Gregory XII, who was ousted from Gaeta and moved to Rimini.
The peace, however, had been only a means to gain time for both John XXIII, who did not want to pay the 75,000 florins, and Ladislaus, who feared intervention in Italy by Sigismund of Hungary.
After Florence initiated diplomatic contacts with Sigismund, Ladislaus marched northwards in mid-May 1413. On 8 June, his troops conquered and sacked Rome, after which he went into Umbria and northern Latium. As it was clearly his next objective, Florence forestalled him by signing a treaty, which recognized Ladislaus' conquest of the Papal States (only Todi and Bologna had not fallen).
Having fallen ill in July 1414, Ladislaus was forced to return to Naples, where he died on 6 August 1414 (coincidentally, the second anniversary of his mother's death). Rumours that he had been poisoned remain unproven: it is more likely that he fell ill due to an infection to his genitals. He is buried in the church of San Giovanni a Carbonara, where a monument was built over his tomb. He was succeeded by his sister Joanna II of Naples, the last member of the senior Angevin line in Italy.
Ladislaus married three times:First to Costanza Chiaramonte in 1390. She was a daughter of Manfredi III Chiaramonte. They were divorced in 1392.
Second to Mary of Lusignan (1381–1404) on 12 February 1403 in Naples. She was a daughter of James I of Cyprus. She died on 4 September 1404.
Third to Mary of Enghien (1367 or 1370 – 9 May 1446), suo iure Countess of Lecce, daughter of John of Enghien, in 1406. She survived him by thirty-two years.
There were no children from any of his marriages. However Ladislaus had at least two illegitimate children:Reynold of Durazzo, Titular "Prince of Capua", buried in Foggia. Married and had children of his own:
Francis of Durazzo. Married and had a son:
Reynold di Durazzo (1469 – 1 September 1494 and buried in Foggia), married to Camilla Tomacelli, without issue
Catherine of Durazzo
Camilla of Durazzo
Hippolyta of Durazzo
Mary of Durazzo, who died young