Gersau is a municipality and district in the canton of Schwyz in Switzerland, sitting on the shores of Lake Lucerne.

On 9 July 1386, the citizens of Gersau fought with the Swiss for the first time, on the battlefield of Sempach, where the banner of Count Rudolf of Hohenzollern was captured.

It was created in 1390 when the residents of the village of Gersau bought themselves free from the rule by bailiffs from Lucerne and from then on exercised their rights themselves.

In 1433 they were officially granted the status of a direct imperial free state in the Holy Roman Empire by Emperor Sigismund.

Within the Confederation, the republic was a place that turned towards it and was under the protection and patronage of the four forest sites (Luzern, Schwyz, Uri and Unterwalden).

After the end of Napoleon's rule, the inhabitants again proclaimed the Republic of Gersau in 1814, which was recognized by the old umbrella towns.

Based on the provisions of the Congress of Vienna and the Federal Treaty of 1815, the canton of Schwyz strove to incorporate the 23.7 square kilometer republic located between the southern slope of the Rigi and the northern shore of Lake Lucerne.

During the French Revolutionary Wars Gersau was annexed into the Helvetic Republic, becoming a district of the canton of Waldstätten.

After the Act of Mediation and the collapse of the Helvetic Republic, Gersau became a district of the canton of Schwyz until 1814, when it regained its independence, with Schwyzer approval, centred on the 1745 Rathaus, containing council chambers and a courtroom (now a museum).

Gersau is in a self-contained location, nestled in a sunny recess in the lee of the south face of Rigi.

This produces a mild climate in which Sweet Chestnut trees thrive, and as a result of which Gersau is known in the region as the Riviera of Lake Lucerne.

Of the rest of the land, 5.7% is settled (buildings or roads) and the remainder (1.7%) is non-productive (rivers, glaciers or mountains).

Gersau has been a well-known health and vacation resort since 1860, with a significant number of hotels and guest houses.