The village of
Salodurum was founded in the time of the Roman emperor
Tiberius (1st century CE). The territory of the canton comprises land acquired by the former town, mainly in the Middle Ages. For that reason the canton is irregular in shape and includes two exclaves along the French border, separated from the rest of the canton by
Basel-Landschaft. In 1481, the canton became a member of the military alliance of the former Swiss confederation. At the end of the
Reformation, Solothurn maintained its Catholic religion. Between 1798 and 1803 the canton was part of the
Helvetic Republic. In 1803 Solothurn was one of the 19 Swiss cantons that were reconstituted by Napoleon (
Mediation). In 1830, the population rebelled against the aristocratic regime and the canton became definitely liberal-democratic. Even though the population was strictly
Roman Catholic, Solothurn did not join the Catholic separatist movement (
Sonderbund) in 1845–7. Similarly, the
federal constitutions of 1848 and 1874 were approved. The current constitution of the canton dates from 1987. ==Geography==