According to Wikipedia, “The First Italian War, sometimes referred to as the Italian War of 1494 or Charles VIII’s Italian War, was the opening phase of the Italian Wars.” The members of the Italian War were Charles VIII of France and Milanese aid against the Holy Roman Empire, Spain, and an alliance of Italian powers known as the League of Venice lead by Pope Alexander VI.
The war began when Charles VIII of France was encouraged to invade Italy while using the Angevin claim to the throne of Naples as a pretext. Charles VIII began conquering city after city leaving all of the other Italian states shocked at these attacks. Pope Alexander VI finally had enough of this and formed the League of Venice. Together, the League of Venice defeated France in the Battle of Fornovo and drew them back. Charles VIII retreated back to France and died before he could launch another attack on the Italian states.