Why was the italian peninsula divided ap euro?

After the fall of the Western Roman Empire, and the rise of Feudalism, many different Kingdoms were established. Other parts were ruled by the Byzantines, The Holy Roman Empire, and various city states. However, after the Italian Wars, (Which rose  from disputes over the Duchy of Milan and the Kingdom of Naples, later the wars rapidly became a general struggle for power and territory among world powers, and were marked with an increasing number of alliances, counter-alliances, and betrayals) The victors took territories
 that they had "won" during the wars.

Delaware, pennsylvania, new jersey, georgia, connecticut, massachusetts bay, maryland, south carolina, new hampshire, virginia, new york, north carolina, and rhode island and providence plantations where the 13 original colonies