Italy
The difficulties of victory
The Neapolitans liked their French oppressors no better than those of Aragon. Rebellions and riots broke out quickly and Charles was unable to quell them, in part because the kingdom was so large but also because the local barons had a long tradition of rebellion.
Within a month, Charles was making plans to escape. In theory he left behind a French government, but in reality the Aragonese were poised to return.
Worse for the French, the north Italian powers had come to realize their peril. The French army could defeat any of them, so they were all at risk. In this atmosphere, Pope Alexander VI (a Borgia, with strong Spanish connections) led the creation (in March 1495) of a new alliance, the first since Lodi in 1494, known as the League of Venice because that's where the agreement was signed. It included the papacy, Milan, Venice, Aragon and the Empire.
Battle of Fornovo
Charles left as quickly as he could. He had only about 20,000 troops left, but he still had his artillery. The League forces met him at Fornovo, in Lombardy about 40 miles south of Milan. When the battle broke out on 6 July it was raining, so the field artillery did not play a role. There was a short, sharp battle that left the League in possession of the field, but the French army was still intact.
The French withdrew, and the League chose not to engage with him again. The first invasion was over. On the surface it seemed that little had been accomplished, and indeed nothing political had any permanence; nevertheless, much had changed and this invasion was symbolic of the changes.