| Philip I | |
| Prince of Taranto, Prince of Achaea, King of Albania, Despot of Romania | |
| Reign: | 1313–1331 |
| Predecessor: | Catherine II (as sole ruler) |
| Successor: | Catherine II (as sole ruler) |
| Regent: | Catherine II |
| Reg-Type: | Co-ruler |
| Reign2: | 13 August 1294 – 1331 |
| Spouse: | Thamar Angelina Komnene Catherine II of Valois |
| Issue: | Charles of Taranto Philip, Despot of Romania Jeanne, Queen of Armenia Margaret of Taranto Blanche of Taranto Robert of Taranto Louis of Taranto Mary of Taranto Philip II of Taranto |
| House: | Anjou-Sicily Anjou-Taranto (founder) |
| Father: | Charles II of Naples |
| Mother: | Maria of Hungary |
| Birth Date: | 10 November 1278 |
| Death Date: | 1331/2 |
Philip I of Taranto (10 November 1278 – 26 December 1331), of the Angevin house, was titular Latin Emperor of Constantinople (as Philip II) by right of his wife Catherine of Valois–Courtenay, Despot of Romania, King of Albania, Prince of Achaea and Taranto.
Born in Naples, Philip was a younger son of Charles II of Anjou, King of Naples, and Maria of Hungary, daughter of King Stephen V of Hungary.
On 4 February 1294, his father named him Prince of Taranto at Aix-en-Provence, and on 12 July 1294, Vicar-General of the Kingdom of Sicily. These dignities were a prelude to Charles' plan to bestow upon Philip an empire east of the Adriatic. The day he was invested as Vicar-General, he married by proxy Thamar Angelina Komnene, daughter of Nikephoros I Komnenos Doukas, Despot of Epirus. Threatened by the Byzantine Empire, Nikephoros had decided to seek Angevin patronage, and agreed to the marriage of Thamar and Philip. The two were married in person on 13 August 1294 at L'Aquila. Upon their marriage, Charles ceded to Philip the suzerainty of Achaea and the Kingdom of Albania, and all his rights to the Latin Empire and the Lordship of Vlachia. Nikephoros gave, as his daughter's dowry, the fortresses of Vonitsa, Vrachova, Gjirokastër and Naupactus, in the territory of Aetolia, to Philip, and agreed to settle the succession, on his death, upon his daughter rather than his son Thomas. Upon the death of Nikephoros (c. 1297), Philip took the title of "Despot of Romania", claiming Epirus, Aetolia, Acarnania, and Great Vlachia. However, Nikephoros' Byzantine widow, Anna Kantakouzene, had Thomas proclaimed Despot of Epirus and assumed the regency.
As Vicar-General of Sicily, he was part of the invasion of that island during the latter stage of the War of the Sicilian Vespers. His army was defeated in 1299 at the Battle of Falconara by Frederick III of Sicily, and he was held prisoner until the signing of the Treaty of Caltabellotta in 1302.
In 1306, Philip of Savoy and Isabella of Villehardouin, the Prince and Princess of Achaea, visited Charles' court in Naples. Philip of Savoy was accused of disloyalty and failure to support Charles in a campaign against Epirus. As Isabelle had not sought her suzerain's consent before marrying him, Charles deprived the two of Achaea and bestowed it directly upon Philip of Taranto on 5 May 1306. He made his only personal visit to Achaea shortly thereafter, accepting the homage of his vassals at Glarentza, and carrying out an unsuccessful campaign against the Despotate of Epirus. He left Guy II, Duke of Athens, as his bailli in Achaea. Meanwhile, Philip and Isabella relinquished their claims on Achaea on 11 May 1307 in exchange for the County of Alba.
In 1309, Philip accused Thamar of adultery, probably on a falsified charge. This freed him to take part in a complex marital pact. Catherine of Valois, the titular Latin Empress, had been betrothed to Hugh V, Duke of Burgundy, titular King of Thessalonica. This engagement was broken, and she married Philip on 29 July 1313, at Fontainebleau. In exchange, her maternal lands of Courtenay and other estates on the Continent were ceded to Hugh's sister Joan the Lame, who married Catherine's half-brother, Philip of Valois. Hugh V was betrothed to Joan of France, later Countess of Burgundy and Artois. (Hugh died before in 1315 before the marriage could be solemnized; Joan of France married Hugh's brother and successor Odo IV, Duke of Burgundy instead.) Philip ceded the Principality of Achaea (over which he retained suzerainty) to Matilda of Hainaut, who married Hugh's brother Louis of Burgundy on 29 July 1313. This donation was rather restricted: should the couple die without heirs, the Principality was to revert to the house of Burgundy, while Matilda enjoyed the usufruct for life. Nor could Matilda marry again without her suzerain's permission. To complete the separation of Eastern and Western claims, Hugh ceded his rights to Thessalonica to Louis, while Louis renounced his claims on his parents' inheritance in favor of Hugh. The engagement of Philip's eldest son Charles of Taranto to Matilda of Hainault was broken off, and he was engaged to Jeanne de Valois, younger sister of Catherine of Valois; his father also ceded to him the title of Despot of Romania and the claims thereto appertaining.
In 1315, Philip was sent by his brother Robert of Naples to lead an army relieving the Florentines, who were threatened by the Pisans under Uguccione della Faggiuola. The Florentine-Neapolitan army was badly beaten at the Battle of Montecatini on 29 August 1315; Philip's younger brother Peter, Count of Gravina and his son Charles of Taranto were both killed.
The death of Louis of Burgundy without heirs in 1316 upset the Angevin plans for Achaea. Matilda was invited to marry John of Gravina, Philip's younger brother, by their elder brother, Robert of Naples. When she declined, she was kidnapped and brought to Naples. By long persuasion and threats, she was compelled in 1318 to consent to the marriage, whereupon Frederick Trogisio was sent to Achaea as a new baili. In 1320, Eudes IV, Duke of Burgundy, after several protests, agreed to sell his rights to Achaea and Thessalonica to Louis, Count of Clermont for 40,000 livres. However, Philip, financed by Philip V of France, bought the claims for the same sum in 1321. In the meantime, the refractory Matilda of Hainaut was brought before the Papal court in Avignon, where she revealed that she had secretly married the Burgundian knight Hugh de La Palice. Her marriage with John was annulled on the grounds of non-consummation, but the revelation of her secret marriage again furnished a pretext for the confiscation of Achaea by the Angevins. It was, of course, bestowed directly upon John of Gravina, in exchange for 40,000 livres, the price paid to the Duke of Burgundy. Matilda spent the rest of her unfortunate life as a prisoner of the Neapolitan state, to prevent the resurgence of her claim.
Philip continued to plot the recovery of the Latin Empire, making an alliance in 1318 with his nephew Charles I of Hungary for that purpose, but to no effect. In 1330, the last of his sons by his first marriage died, returning to him the title of Despot of Romania. All his rights and titles passed on his death two years later to his eldest son by his second marriage, Robert of Taranto.
Children of his first marriage (1294), with Thamar Angelina Komnene, which ended with a divorce (1309):
Children of his second marriage (1313), with Catherine of Valois: