The fortress of Cetin is situated 5 kilometres south of Cetingrad above the village of Podcetin. The date when Cetin was founded is unknown. There are some indications that a settlement existed there in the times of the Roman Empire. The Parish of All Saints, in which the fortress is situated, was first mentioned in 1334. In 1387, king Sigismund, Holy Roman Emperor gifted Cetin to Ivan Krčki. Thereby it became the property of the Frankopan family.
The Middle Ages were the golden era of Cetin. There was a Franciscan monastery and several churches near the fortress. In the 15th century, the Cetinski branch of Frankopan family was formed. It only lasted a hundred years. Ivan Frankopan Cetinski died in the Battle of Krbava field. His brother Grgur and son Franjo Frankopan became archbishops of Kalocsa. Franjo Frankopan was the last member of the Frankopan Cetinski family. After him, the fortress became property of the Frankopan Slunjski family.
Cetin played an important role in the history of Croatia. After the defeat at the Battle of Mohács in 1526, Croatian nobility gathered at the Parliament on Cetin (Cetinski sabor). On 1 January 1527, they elected Ferdinand Habsburg, Archduke of Austria as the king of Croatia. The chart signed by Croatian nobles and representatives of Ferdinand of Habsburg is among the most important documents of Croatian statehood and is preserved in the Austrian State Archives in Vienna.
In the following centuries, Cetin was part of the Military Frontier, the borderland between the Habsburg Monarchy and the Ottoman Empire. During this period, Ottoman army took control of it several times. The fortress was often damaged and repaired. Two stone plates with Arabic inscriptions in the Croatian History Museum testify about reconstructions made during this period. In 1790, Austrian troops under the command of general Walisch finally won back Cetin for the Habsburg monarchy. The siege took one month, and after the battle several officers were decorated, including Johann I Josef, Prince of Liechtenstein. Cetin's status was finally confirmed during the peace conference in Svishtov. In 1809, Ottoman forces once again occupied Cetin but they withdrew the following year under the threats of Marshal Marmont, governor-general of Illyrian provinces. Once the Ottoman threat petered out the fortress was abandoned and turned into a quarry. Administrative control of the surrounding area was transferred to the village of Cetingrad, which developed north of Cetin.
Royal Palace of Naples was one of the four residences near Naples used by the Bourbon Kings during their rule of the Kingdom of the Two Sicilies (1734-1860): the others were the palaces of Caserta, Capodimonte overlooking Naples, and the third Portici, on the slopes of Vesuvius.
Construction on the present building was begun in the 17th century by the architect Domenico Fontana. Intended to house the King Philip III of Spain on a visit never fulfilled to this part of his kingdom, instead it initially housed the Viceroy Fernando Ruiz de Castro, count of Lemos. By 1616, the facade had been completed, and by 1620, the interior was frescoed by Battistello Caracciolo, Giovanni Balducci, and Belisario Corenzio. The decoration of the Royal Chapel of Assumption was not completed until 1644 by Antonio Picchiatti.
In 1734, with the arrival of Charles III of Spain to Naples, the palace became the royal residence of the Bourbons. On the occasion of his marriage to Maria Amalia of Saxony in 1738, Francesco De Mura and Domenico Antonio Vaccaro helped remodel the interior. Further modernization took place under Ferdinand I of the Two Sicilies. In 1768, on the occasion of his marriage to Maria Carolina of Austria, under the direction of Ferdinando Fuga, the great hall was rebuilt and the court theater added. During the second half of the 18th century, a 'new wing' was added, which in 1927 became the Vittorio Emanuele III National Library. By the 18th century, the royal residence was moved to Reggia of Caserta, as that inland town was more defensible from naval assault, as well as more distant from the often-rebellious populace of Naples.
During the Napoleonic occupation the palace was enriched by Joachim Murat and his wife, Caroline Bonaparte, with Neoclassic decorations and furnishings. However, a fire in 1837 damaged many rooms, and required restoration from 1838 to 1858 under the direction of Gaetano Genovese. Further additions of a Party Wing and a Belvedere were made in this period. At the corner of the palace with San Carlo Theatre, a new facade was created that obscured the viceroyal palace of Pedro de Toledo.
In 1922, it was decided to transfer here the contents of the National Library. The transfer of library collections was made by 1925.
The library suffered from bombing during World War II and the subsequent military occupation of the building caused serious damage. Today, the palace and adjacent grounds house the famous Teatro San Carlo, the smaller Teatrino di Corte (recently restored), the Biblioteca Nazionale Vittorio Emanuele III, a museum, and offices, including those of the regional tourist board.