While the Act of Mediation remained in force until the end of Napoleon's power in 1813 and was an important step in the development of the Swiss Confederation, the rights promised in the Act of Mediation soon began to vanish. In 1806 the principality of Neuchâtel was given to Marshal Berthier. Ticino was occupied by French troops from 1810 to 1813. Also, in 1810 the Valais was occupied and converted into the French department of the Simplon to secure the Simplon Pass. Swiss troops still served in foreign campaigns such as the French invasion of Russia which undermined their long-held neutrality. At home the liberty of moving from one canton to another (though given by the constitution) was, by the Diet in 1805, restricted by requiring ten years' residence, and then not granting political rights in the canton or a right of profiting by the communal property.