The new trade route made those regions far from the centers of power look interesting for the counts of Habsburg (northern Switzerland) who were trying at the time to strengthen their dynastic power. As a reward for help in several war expeditions to Italy, German king Friedrich II exempted the valleys of Uri (1231) and Schwyz (1240) from the jurisdiction of any counts and dukes so they would be subject to the king alone.
When his successor king Rudolf of Habsburg, the first German Emperor from this house, died in 1291, people from Uri, Schwyz and Unterwalden feared that the counts of Habsburg would try to regain influence in their territories. So they swore to help each other against anyone attempting to subject them. This is the historical background of the legend of the Oath on Rütli (a meadow on the western shore of Lake Lucerne, see picture). While the Federal Charter (Bundesbrief), dated from "the first days of August, 1291" is a historical fact and can be seen at the Museum of the federal charters in Schwyz [during summer of 2006, the federal charter has been on exhibition in the USA for a few weeks], the Oath on Rutli is a legend (anyway well composed, because of the secret nature of the beginning of the history of the old Swiss confederacy). Towards the end of the 19th century, August 1st was introduced as a national holiday.
The William Tell Overture, in observance of Switzerland's national day.