A reply to /u/NikKerk
Refashion from a previous post
Swiss pikemen were famous because with their discipline, they were able to both counter the heavy cavalry and move on the offensive. Thanks to their mercenary tradition, they were well-drilled, disciplined, fearless, and for the most parts quite loyal.
How did this tradition come about? One reason is that Swiss lands were not the most wealthy, in that era they had mostly pastoral lands with little to trade for. So they had a long tradition of campaigning in the summer, between planting and harvesting. Another reason is their traditional enmity against the HRE, so they had to maintain a certain level of military readiness. This ended up being a canton-by-canton militia system, which led to constant training throughout the year.
The Swiss proved their mettle in the battles of Grandson and Murten where they beat the Burgundians through aggressive movements, nearly literally running over Burgundian defenses in bad weather despite the Burgundians having set up a defensive posture with artillery.
Not only were they fearsome when winning, they were also impressive in defeat. At Marignano, their disciplined retreat enabled them to maintain strategic power. Not only that, but the Swiss who fought at Marginano did so after offers from Francis to buy them off their Milanese employers. A small number of Swiss units did accept the bribe, but a majority decided to stay and fight, even knowing it was a fight they would not win. So impressive were they that France entered into "Eternal Peace" with the Swiss following that battle, with King Francis I himself declaring, "I have defeated those that only Caesar has defeated."
But their military prowess was not the only factor. Their tradition of campaigning each year means they could be a reliable source of mercenary manpower, and they became important parts of French armies in the Italian wars. Swiss communities included military training in their tradition, so they had a reliable supply of trained troops.
However, the Swiss sometimes let greed get ahead of them. As they relied on plunder as a means to boost their income, they forced their French employers into a pitched battle at Bicocca when they did not get their demand for pay. Unfortunately, the Spanish Imperial troops had set up a defensive position that held against Swiss assaults.
The Spanish commander Gonzalo Fernandez de Cordoba eventually invented a new fighting system called the colunellia which became the basis of the tercio where close-order coordination between firearms and pikes could beat the pike-heavy Swiss formations. Over time, the Spanish were able to win the Italian wars, including the ignoble defeat and capture of Francis I in the 1525 Battle of Pavia.
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