Switzerland’s geographical position with its transit routes over the Alps made it a desirable possession for European great powers through the ages.
Switzerland developed slowly over many centuries, as more and more regions came together to form a loose confederation whose members gave each other mutual support. At times their different interests stretched the bonds between them almost to breaking point.
It was only in 1848 that Switzerland became a more centralised federal state. This favoured its economic development and ended any possibility that Switzerland might break up.
Learn more about Swiss history: http://www.swissworld.org/en/history/