During the War of Austrian Succession, in 1742 Charles sent an army corp to Lombardy to help the French-Spanish army (all lineages of the Bourbon family were allied); however, it happened that a British fleet appeared in the Gulf of Naples and threatened Naples with shelling the city; Charles decided to withdraw his army corp, which made Paris and Madrid angry. But he was able to redeem himself in 1744, when he completely defeated an Austrian army at Velletri, put a final end to the Hapsburg claims over Naples, and succeeded in setting himself free from the tutelage of Madrid. By this victory, Charles began to act as the real king of Naples. The Kingdom became independent in all respects. This became even clearer in 1746, when Philip V of Spain died and Elisabeth was set to one side: in fact Charles dismissed Montealegre and replaced him with Fogliani. Valsecchi wrote: «« Until then, Charles’ reign had been a Spanish-Italian monarchy: from that moment on, it became an Italian monarchy».

In fact, from that moment on Charles became the real “King of Naples” in full agreement with his people and their needs. As years went by, he rose above the influence of his ministers and became a great sovereign and the real author of his policy by centralizing power in his hands: «Squillace and Tanucci, who occupied the most important positions, were his creatures; and although they enjoyed his confidence, were limited in their powers and subject to his direct surveillance» .

After five daughters, Maria Amalia gave Charles his first son, but unfortunately the baby was mentally disabled; after him, other four sons were born (Charles Antonio, Ferdinand, Gabriel and Francis Xavier), thus assuring the succession.

However, "dynastic" threats hung over the kingdom. In fact Charles was destined to succeed his step-brother Ferdinand VI on the Throne of Spain, since the latter had no male heirs and the great powers had established by the League of Aranjuez and the Treaty of Vienna that his kingdom would go to the Duke of Parma and Piacenza, Philip of Bourbon, and that the two Duchies would go to Austria and Savoy respectively. In reality, to ascend the Throne of Madrid, Charles risked to loose the kingdom he had conquered for himself.

King Charles signs his Proclamation of 1759

He always did his best so that this "misunderstanding" (as he called it) would not occur: and he was successful and favoured by international situations. When in 1759 Ferdinand VI died, he succeeded him on the Throne of Madrid with the name of Charles III, and, renounced the crowns of Naples and Sicily (as foreseen by the Bourbon hereditary regulations; Charles strengthened this decision by issuing a Proclamation on 6 October 1759 by which he, once King of Spain, finally ratified the irreversible process of separation of the two Royal Families), and gave them to his third son Ferdinand, who at that time was only eight (his second son Charles Antonio followed him to Spain as heir to the Throne).

The regency was given to eight ministers, among which Tanucci, Prime Minister and Minister of Foreign Affairs, but always under the supervision of Charles from Spain. «Naples owed him the greatest benefit: independence and all its good consequences, after 230 years of foreign rule», as Michelangelo Schipa wrote in "Enciclopedia Italiana" (sub voce).

The last years of his life would be embittered by his disagreement with his son in Naples and in particular with his wife, Maria Carolina, Empress Maria Teresa’s daughter, resolved to break the Spanish influence at the Court. His work, however, would remain unforgettable in the history of Naples. He died in 1788.

In fact, Charles’ main merit is that of restoring the “Neapolitan State”, making the Kingdom independent and sovereign, as also Spagnoletti wrote. Although the most important and recent studies are now re-evaluating the Hapsburg policy of the previous centuries (see Elìas de Tejada’s works), it is out of doubt that only after the crowning of Charles the Neapolitan government, its sovereigns and ministers began to think and act in the exclusive interest of the Kingdom of Naples and its inhabitants. Weighing the achievements of Charles’ rule in Naples, the historian Giuseppe Coniglio wrote: «Charles, at the eve of his departure for Spain (…) had settled whatever he could foresee and had obtained the approval of the great powers (…) Charles’ sons and brother would reign without problems and handed down the Throne to their heirs; the diplomatic construction turned out to be efficient and up to meet very difficult and stormy moments, overcoming hard times both in Spain and Italy» .

Moreover, the famous historian Franco Valsecchi wrote : «To the Neapolitans, Charles’ crowning was more than a simple change of dynasty. It was the restoring of the ancient kingdom, after centuries of foreign rule (…) The governments that followed each other in the first thirty years of that century were foreign governments, distracted from far and alien worries. Also the new king was a foreigner; but he did not come as a foreign ruler. The hopes of the Neapolitans were lighted up: "thanks God we are no longer provincials". It was up to the new national dynasty to interpret the new reality and its needs». And the Neapolitans felt involved and in agreement with the new dynasty, as they would show from 1799 on by their uprisings and Sanfedismo, their armed resistance against the Napoleonic invaders.