Under Bajazet, the successor, there was some rest for Europe. His brother, who was a dangerous competitor, as the crown went to the one who survived, fled for safety to the Christians, and was detained as a hostage, beyond the possibility of ransom, by the Knights of St. John, and then by the Pope. The Sultan paid, that he might be kept quiet.
For years the Turks were busy in the East. Selim conquered Syria and part of Persia. He conquered Arabia, and was acknowledged by the Sheriff of Mecca caliph and protector of the holy shrine. He conquered Egypt and assumed the prerogative of the Imaum, which had been a shadow at Cairo, but became, at Constantinople, the supreme authority in Islam. Gathering up the concentrated resources of the Levant, Solyman the Magnificent turned, at last, against the enemy who guarded the gates of civilised Europe. Having taken Belgrade, he undertook, in 1526, the crowning campaign of Turkish history. At the battle of Mohacs Hungary lost her independence. The Turks found a Transylvanian magnate who was willing to receive the crown from them; and the broad valley of the Danube continued to be their battlefield until the days of Sobieski and Eugene. But the legitimate heir of King Ladislas, who fell at Mohacs, was Ferdinand, only brother of Charles V; and Hungary, with the vast region then belonging to the Bohemian crown, passing to the same hands as the ancient inheritance of the Habsburgs, constituted the great Austrian monarchy which extended from the Adriatic to the far Sarmatian plain, and Solyman's victory brought him face to face with the first Power able to arrest his progress. The Turks were repulsed at Vienna in 1529, at Malta in 1564. This was their limit in Western Europe; and after Lepanto, in 1571, their only expansion was at the expense of Poland and Muscovy. They still wielded almost boundless resources; the entire seaboard from Cattaro all round by the Euxine to the Atlantic was Mahomedan, and all but one-fourth of the Mediterranean was a Turkish lake. It was long before they knew that it was not their destiny to be masters of the Western as well as of the Eastern world.
While this heavy cloud overhung the Adriatic and the Danube, and the countries within reach of the Turk were in peril of extinction, the nations farther west were consolidating rapidly into unity and power. By the marriage of Ferdinand and Isabella, by their conquest of Granada and the rise of a new hemisphere at their command, Spain for the first time became a great Power; while France, having expelled the English, having instituted a permanent army, acquired vast frontier provinces, and crushed the centrifugal forces of feudalism, was more directly formidable and more easily aggressive. These newly created Powers portended danger in one direction. Their increase was not so much in comparison with England or with Portugal, as in contrast with Italy. England, through the Tudors, had achieved internal tranquillity; and Portugal was already at the head of Europe in making the ocean tributary to trade. But Italy was divided, unwarlike, poor in the civic virtues that made Switzerland impregnable, rich in the tempting luxuries of civilisation, an inexhaustible treasure-house of much that the neighbours greatly needed and could never find elsewhere. The best writers and scholars and teachers, the most consummate artists, the ablest commanders by land and sea, the deepest explorers of the mystery of State that have been known before or since, all the splendours of the Renaissance, and the fruits of a whole century of progress were there, ready to be appropriated and employed for its own benefit by a paramount Power.
It was obvious that the countries newly strengthened, the countries growing in unity and concentration and superfluous forces, would encroach upon those that were demoralised and weakened. By strict reason of State, this was not the policy of France; for the French frontiers were assigned by nature everywhere but in the north-east. There the country was open, the enemy's territory approached the capital; and the true line of expansion was towards Antwerp, or Liege, or Strasburg. But the French were invited into Italy with promise of welcome, because the Angevin claim to Naples, defeated in 1462, had passed to the King of France. The Aragonese, who had been successful in resisting it, was not legitimate, and had been compelled again to struggle for existence by the Rising of the Barons. The rising was suppressed; the discontented Neapolitans went into exile; and they were now in France, prophesying easy triumphs if Charles VIII would extend his hand to take the greatness that belonged to the heir of the house of Anjou. They were followed by the most important of the Italian Cardinals, Della Rovere, nephew of a former Pope, himself afterwards the most famous pontiff who had appeared for centuries. Armed with the secrets of the Conclave, the Cardinal insisted that Alexander VI should be deposed, on the ground that he had paid for the papacy in ascertainable sums of money and money's worth; whereas spiritual office obtained in that way was ipso facto void.
The advent of the French, heralded by the passionate eloquence of Savonarola, was also hailed by Florence and its dependencies, in their impatience of the Medicean rule, now that it had dropped from the hands of the illustrious Lorenzo into those of his less competent son. Lodovico Sforza, the Regent of Milan, was also among those who called in the French, as he had a family quarrel with Naples. His father, Francesco, the most successful of the Condottieri, who acquired the Milanese by marriage with a Visconti, is known by that significant saying: "May God defend me from my friends. From my enemies I can defend myself." As the Duke of Orleans also descended from the Visconti, Lodovico wished to divert the French to the more alluring prospect of Naples.
In September 1494 Charles VIII invaded Italy by the Mont Genevre, with an army equal to his immediate purpose. His horsemen still displayed the medieval armour, wrought by the artistic craftsmen of the Renaissance. They were followed by artillery, the newer arm which, in another generation, swept the steel-clad knight away. French infantry was not thought so well of. But the Swiss had become, in their wars with Burgundy, the most renowned of all foot-soldiers. They were unskilled in manoeuvres; but their pikemen, charging in dense masses, proved irresistible on many Italian fields; until it was discovered that they would serve for money on either side, and that when opposed to their countrymen they refused to fight. At Pavia they were cut down by the Spaniards and their fame began to wane. They were Germans, hating Austria, and their fidelity to the golden lilies is one of the constant facts of French history, until the Swiss guard and the white flag vanished together, in July 1830.
Charles reached Naples early in 1495, having had no resistance to overcome, but having accomplished nothing, and having manifested no distinct purpose on his way, when he found himself, for a moment, master of Florence and of Rome. The deliverance of Constantinople was an idea that occurred inevitably to a man of enterprise who was in possession of Southern Italy. It was the advanced post of Europe against the East, of Christendom against Islam; the proper rendezvous of Crusaders; the source of supplies; the refuge of squadrons needing to refit. The Sultan was not an overwhelming warrior, like his father; he had not, like Selim, his successor, control of the entire East, and he was held in check by the existence of his brother, whom Charles took with him, on leaving Rome, with a view to ulterior service, but whom he lost soon after.
Charles VIII was not a man ripened by experience of great affairs, and he had assumed the title of King of Jerusalem, as a sign of his crusading purpose. But he also called himself King of Sicily, as representing the Anjous, and this was not a disused and neglected derelict. For the island belonged to the King of Aragon, the most politic and capable of European monarchs. Before starting for Italy, Charles had made terms with him, and Ferdinand, in consideration of a rectified frontier, had engaged, by the Treaty of Barcelona, to take no unfriendly advantage of his neighbour's absence. The basis of this agreement was shattered by the immediate unexpected and overwhelming success of the French arms. From his stronghold in the South it would be easy for Charles to make himself master of Rome, of Florence, of all Italy, until he came in sight of the lion of St. Mark. So vast and sudden a superiority was a serious danger. A latent jealousy of Spain underlay the whole expedition. The realm of the Catholic kings was expanding, and an indistinct empire, larger, in reality, than that of Rome, was rising out of the Atlantic. By a very simple calculation of approaching contingencies, Ferdinand might be suspected of designs upon Naples. Now that the helplessness of the Neapolitans had been revealed, it was apparent that he had made a false reckoning when he allowed the French to occupy what he might have taken more easily himself, by crossing the Straits of Messina. Ferdinand joined the Italians of the North in declaring against the invader, and his envoy Fonseca tore up the Treaty of Barcelona before the face of the French king.
Having been crowned in the Cathedral, and having garrisoned his fortresses, Charles set out for France, at the head of a small army. As he came over the Apennines into Lombardy, at Fornovo he was met by a larger force, chiefly provided by Venice, and had to fight his way through. A fortnight after his departure, the Spaniards, under Gonsalvo of Cordova, landed in Calabria, as auxiliaries of the dethroned king. The throne was once more occupied by the fallen family, and Charles retained nothing of his easy and inglorious conquests when he died in 1498.
His successor, Lewis XII, was the Duke of Orleans, who descended from the Visconti, and he at once prepared to enforce his claim on Milan. He allied himself against his rival, Sforza, with Venice, and with Pope Alexander. That he might marry the widowed queen, and preserve her duchy of Brittany for the Crown, he required that his own childless marriage should be annulled. Upon the Legate who brought the necessary documents the grateful king bestowed a principality, a bride of almost royal rank, and an army wherewith to reconquer the lost possessions of the Church in Central Italy. For the Legate was the Cardinal of Valencia, who became thenceforward Duke of Valentinois, and is better known as Caesar Borgia. The rich Lombard plain, the garden of Italy, was conquered as easily as Naples had been in the first expedition. Sforza said to the Venetians: "I have been the dinner; you will be the supper"; and went up into the Alps to look for Swiss levies. At Novara, in 1500, his mercenaries betrayed him and he ended his days in a French prison. On their way home from the scene of their treachery, the Swiss crowned their evil repute by seizing Bellinzona and the valley of the Ticino, which has remained one of their cantons.