 Complete the following phrase:  The term mountain warfare is said to have come about in the Middle Ages after the monarchies of Europe found it difficult to fight the Swiss armies in the Alps because the Swiss were able to fight in smaller units and took vantage points against a huge unmaneuverable army. Similar styles of attack and defence were later employed by guerrillas, partisans and irregulars who hid in the mountains after an attack, making it challenging for an army of regulars to fight back. In Bonapartes Italian campaign and the 