Nor could the King of Sicily remain a tranquil spectator, while his neighbour and relative was displaced by a new and aggressive power. Louis determined to compromise, and (November, 1500) concluded at Granada a secret treaty with Aragon for a joint conquest of Naples, conceding to Ferdinand a fair half of the kingdom, and, provisionally, the provinces of Apulia and Calabria.
Strengthened by this compact, Louis was free to move. In May, 1501, his army was ready in Lombardy. With the certainty of Spanish aid, 1,000 lances, 4,000 Swiss, and 6,000 French infantry were held sufficient. The command was divided between Aubigny, the Count of Caiazzo (Francesco di San Severino), and the Duke of Valentinois. A fleet under Ravenstein was operating on the coast from the convenient base of Genoa. Federigo relied on help from Sicily, where was the great Gonzalo, who had recently returned from a successful expedition against the Turks, and who, acting under orders, was careful not to undeceive him. The first news of the coalition came to Naples from Rome, where in June Alexander issued a bull depriving Federigo of his throne and confirming the partition already arranged between the Kings of France and Aragon. In July the French army reached Capua, which was held by Fabrizio Colonna with a sufficient force. But the French artillery soon made a practicable breach, and, while terms of surrender were being discussed, the French were admitted into the town, which they sacked with every circumstance of cruelty and outrage. There was no further resistance. On August 2 Federigo retired to Ischia, and after a time decided to accept the asylum offered to him by Louis, who provided him with a rich endowment and an honourable position in France. On August 4 French garrisons occupied the castles of Naples, and la Palice was sent to hold the Abruzzi. Louis d'Armagnac, duke of Nemours, was appointed viceroy of the newly acquired kingdom.
Meanwhile Gonzalo without difficulty occupied his master's share of the kingdom of Naples, and was joined by Prospero and Fabrizio Colonna, whose family was about this time expelled from their possessions in papal territory, while Cesare, their bitterest enemy, was leagued with the French. Only at Taranto was there considerable resistance. Here lay Federigo's son, Ferrante. The town was strong, but a siege by sea and land compelled it after a stout resistance to come to terms (March, 1502). Gonzalo promised his liberty to Ferrante, but the Spanish King disregarded the promise, and caused the young prince to be sent in custody to Spain.
The treaty of Granada had not been so carefully drawn as to exclude all possibility of doubt. France was to have the Abruzzi, the Terra di Lavoro, Naples, and Gaeta, while Spain received Apulia and Calabria. But nothing was said about the province of the Capitanata, lying between Apulia and the Abruzzi, about the Basilicata, lying between Calabria and Apulia, or about the two Principati, lying between the Basilicata and