In 1798 French forces crossed the Swiss border. At the time the Old Confederation was experiencing revolutionary changes. An attempt was made to create a unitary Republic of Helvetia, but it failed due to different reasons.
Napoleon withdrew his forces from Switzerland in 1803, but during his presence there he had fully reformed the country and provided it with a new Constitution, actually turning Switzerland into the State as we see it today. It was after Napoleon's involvment that Switzerland became a union of 19 soverein cantons.
In September 1803 a treaty was signed by the French Republic and the Swiss Confederation, by which the latter was obliged to form four infantry regiment, each with an artillery company, to fight on the side of the French.
In essence, those regiments were mercenary formations at French service. The number of Swiss soldiers on French service was 16000, and the Treaty envisaged a term of compulsory service as 4 years.
After that each military man could prolong his service for 2, 4, 6 or 8 years.
One of the Treaty's obligatory conditions was the deployment of Swiss regiments only in the territory of Europe. Another provision of the Treaty read that the Swiss Government had to replace the number of possible deserters at its own expense.
The 1st Regiment was formed in 1805 from the remnants of the "Helvetic demi-brigades” which had served in Republican France. Next year, in October 1806, three more regiments were formed.
Residents of the Valais Canton (Sothern Switzerland) undertook to supply a battalion of infantry to the French army - the Valaison Batalion. However, after that canton was annexed by France in 1811, the formation was incorporated into the French regular army.
Later, on May 11 1807, the Neuchatel Battalion appeared. The Principality of Neuchatel was incorporated into France in 1806, and the Emperor presented it to Prince Berthier along with the title of Prince of Neuchatel.
While fighting for the Empire, the Swiss regiments have shown themselves at their best. They fought galantly and bravely throughout the whole Campaign of 1812. But the major exploit of the Swiss was their participation in the Battle of Berezina, where all four Swiss Infantry Regiments held Russian forces in check, and made it possible for the retreating remnants of the Grand Armee to cross the river.
