aostosopimus

The Aostosopimus, also known as the Åostosopimus in Finnish, refers to a historical agreement signed in Åbo (Turku), Finland, on May 17, 1809. This treaty marked a significant shift in Finland’s political and legal status following the Finnish War (1808–1809), a conflict between Russia and Sweden. The war resulted in Sweden’s defeat, and under the terms of the treaty, Finland was ceded to the Russian Empire by Sweden.

The Aostosopimus established Finland as an autonomous Grand Duchy within the Russian Empire, preserving many of its pre-war institutions, laws, and cultural traditions. Key provisions included the retention of the Finnish legal system, the Lutheran Church as the state religion, and the Finnish language in administration and education. The treaty also granted Finland its own constitution, the Constitution of Finland (1809), which outlined its governance structure, including a Diet (Eduskunta) and a governor-general appointed by the Russian tsar.

The agreement aimed to stabilize Finland by integrating it into the Russian Empire while maintaining its distinct identity. However, over time, Russian centralization policies gradually reduced Finland’s autonomy, culminating in the abolition of its constitution in 1917. The Aostosopimus remains a foundational document in Finnish legal and historical discourse, symbolizing the country’s early efforts to balance sovereignty and foreign rule.