Castel Nuovo Castel Nuovo ( Italian : " New Castle " ) , often called Maschio Angioino , is a medieval castle in the city of Naples , southern Italy . It is the main symbol of the architecture of the city , and has been expanded or renovated several times since it was first begun in 1279 . History . Before the accession of Carlo I of Anjou to the throne in 1266 , the capital of the Kingdom of Naples was Palermo . There was a royal residence in Naples , at the Castel Capuano . However , when the capital was moved to Naples , Charles ordered a new castle , not far from the sea , built to house the court . Works , directed by french architects , began in 1279 and were completed three years later . Due to the War of the Sicilian Vespers , the new fortress remained uninhabited until 1285 , when Charles died and was succeeded by his son , Charles II . Castel Nuovo soon became the nucleus of the historical center of the city , and was often the site of famous events . For example , on December 13 , 1294 , Pope Celestine V resigned as pope in a hall of the castle . Eleven days later , Boniface VIII was elected pope here by the cardinal collegium and immediately moved to Rome to avoid the Angevin authority . Under king Robert ( reigned from 1309 ) , the castle was enlarged and embellished , becoming a centre of patronage of art . In 1347 Castel Nuovo was sacked by the army of Louis I of Hungary , and had to be heavily restored after the return of queen Joanna I . The new works permitted the queen to resist the Hungarian siege during Louis ' second expedition . The castle was besieged numerous times in the following years , and was the official residence of King Ladislaus from 1399 . It decayed under his sister Joanna II . Under the Aragonese dynasty , begun by Alfonso V in 1442 , the fortress was updated to resist the new artillery . A famous triumphal arch , designed by Francesco Laurana , was added to the main gate to celebrate Alfonso ' s entrance in Naples . The decoration was executed by the sculptors Pere Johan and Guillem Sagrera , called by Alfonso from Catalonia . In a hall of the castle the famous Barons conspiracy against King Ferdinand I , Alfonso ' s son , occurred . The King had invited the barons for a feast ; but , a certain point , he had the garrison close all the hall ' s doors and all the barons were arrested and later executed . The Barons ' Hall was the seat of the Council of the commune of Naples until 2006 . After the fierce sack of Naples by Charles VIII of France ' s soldiers in 1494 , the Kingdom was annexed by Spain , and the castle was reduced from residence to an important military fortress . It was the temporary residence of the Spanish kings during their visits in the city , such as that of Charles V in 1535 . The castle was again used as a residence by Charles III and later on by Duke Stefano Di Conza . The last restoration of Castel Nuovo occurred in 1823 . Triumphal Arch at Castel Nuovo . The imposing single - sided white marble triumphal arch , built in 1470 , commemorates Alfonso of Aragon ' s entry to Naples in 1443 . It stands between two western Towers of the Angevin castle . The overall design had been attributed to Pietro di Martina , a Milanese architect , or , according to Vasari , to Giuliauo da Maiano . Modern authors attribute the design to Francesco Laurana . It is 35 meters tall and has been elongated into two stacked arches . Some reports claim that the arches had originally been planned as two face to a free standing arch for the Piazza del Duomo , but that an officer in the service of Alfonso , Niccolo Bozzuto , whose house was to be razed to make room for the monument , induced the king to alter the site to the Castel Nuovo . The self - conscious Renaissance style , appropriates items from Roman triumphal arches , but lacks sobriety , and is encrusted in a profusion of ornamentation with garlands , harpies , festoons , and putti among the elements . The structure is not a true arch , but decoration affixed to the former entrance of the castle . The flanking corinthian columns flank the entrance , but the first level sculpture depicts a triumphal quadriga leading Alfonso parading . The sculptors included Isaia da Pisa , Merliano , Domenico Gagini , Andrea Fiorentino , a pupil of Donatello , and Silvestro dell ' Aquila . Sculptors from Aragon also contributed to the work . The center has a shield with the symbols of Aragon . The Frieze below reads : " ALFONSVS REX HISPANVS SICULVS ITALICUS PIVS CLEMENS INVICTUS " Above it reads : " ALFONSVS REGUM PRINCEPS HANC CONDIDIT ARCEM " The second upper arch is surmounted by Lions and four niches with statues depicting the virtues of Alfonso . Above this is a rounded lintel with two genii with horns of plenty surmounted by Alfonso in attire of a warrior . This cornice was meant for an equestrian statue . The three statues of St . Michael , St . Anthony the Abbot , and St . Sebastian , and the two recumbent ones , on the summit of the arch , are by Giovanni da Nolo . Passing under this arch we enter the piazza by the Bronze Gates , executed by the monk Guglielmo of Naples , and representing in various compartments the victories of Ferdinand I over the Duke of Anjou and the rebellious barons .