Ladislaus the Magnanimous (Italian: Ladislao, Hungarian: László; 15 February 1377 – 6 August 1414) was King of Naples from 1386 until his death and an unsuccessful claimant to the kingdoms of Hungary and Croatia.

Ladislaus was a skilled political and military leader, protector and controller of Pope Innocent VII; however, he earned a bad reputation concerning his personal life.

[2] Ladislaus became King of Naples at the age of nine (1386) under his mother's regency after his father was assassinated while pursuing his claim to the throne of Hungary.

[2] 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 1390, the archbishop of Arles poisoned Ladislaus, and though he survived, he subsequently stuttered and was forced to take repeated periods of rest.

[2] 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.

On 5 August 1403, while in the town of Zara, Ladislaus was crowned king of Hungary and Croatia by János Kanizsai, archbishop of Esztergom, in the presence of the papal legate, Cardinal Angelo Acciajuoli.

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 Neapolitan royal power at the expense of the barons, and brought about the murders of several members of the Sanseverino family for frustrating his ends.

[5] His wife, Mary of Enghien, continued the rebellion and successfully defended Taranto against a two-month long siege by Ladislaus in the spring of 1406.

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.

[6] In 1408, he besieged Ostia to prevent a success of the French party in the schism between Gregory XII and Antipope Benedict XIII.

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.

[8] 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.

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.

The peace was 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.

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).