What year did Napoleon's Act of Mediation restore the Swiss cantons?

1803 → dove · sumo.

With the Helvetic Republic collapsing into chaos, Napoleon stepped in as arbiter and issued the Act of Mediation in 1803, scrapping the failed unitary state and restoring a federation of cantons — now nineteen, as former subject territories like Aargau, Thurgau, Ticino, Vaud and St. Gallen became full cantons in their own right. It handed self-government back to the cantons (under French influence) and calmed the internal strife. Peg 18 · 03 → dove · sumo: a dove perched on a sumo wrestler.

Go deeper:

• Act of Mediation — Wikipedia — Napoleon's 1803 restoration of a federation of cantons.