By Mid-March 1798 Aarau was occupied by French troops.
On 22 March 1798 Aarau was declared the capital of the Helvetic Republic. In 1803, Napoleon ordered the fusion of the cantons of Aargau, Baden and Fricktal.
Two weeks later a French envoy continued to foment the revolutionary opinions of the city.
On 11 August 1712, the Peace of Aarau was signed into effect.
This granted each canton the right to choose their own religion thereby ending Catholicism's control.
The Roman road between Salodurum (Solothurn) and Vindonissa passed through the area, along the route now covered by the Bahnhofstrasse.
In 1976 divers in the Aare found part of a seven-meter wide wooden bridge from the late Roman times.
It is therefore the first capital of a unified Switzerland. Aarau was declared the capital of the new, enlarged canton of Aargau.
In 1820 the city wall was torn down, with the exception of the individual towers and gates, and the defensive ditches were filled in.Aarau and the nearby neighboring municipalities have grown together and now form an interconnected agglomeration.The only exception is Unterentfelden whose settlements are divided from Aarau by the extensive forests of Gönhard and Zelgli.In the 16th century, the rights of the lower classes were abolished.In March 1528 the citizens of Aarau allowed the introduction of Protestantism at the urging of the Bernese.These highly educated immigrants were also responsible for educational reform and the enlightened, revolutionary spirit that developed in Aarau.