Estonian kroon until the Soviet invasion in 1940 and Estonia's subsequent incorporation into the Soviet Union when it was replaced by the Soviet ruble. After Estonia regained its independence, the kroon was reintroduced in 1992. The kroon became the currency of Estonia on 1 September 1928 after having been a unit of account since 1924. It replaced the mark at a rate of 100 mark = 1 kroon. The kroon was subdivided into 100 sent. In 1924, the kroon was pegged to the Swedish krona at par, with a gold standard of 2480 kroon = 1 kilogram of pure gold. The standard
European Monetary System were used to keep the currencies within a narrow range. In the early 1990s the European Monetary System was strained by the differing economic policies and conditions of its members, especially the newly reunified Germany, and Britain (which had initially declined to join and only did so in 1990) permanently withdrew from the system in September 1992. Speculative attacks on the French Franc during the following year led to the so-called Brussels Compromise in August 1993 which established a new fluctuation band of +15%. European currency exchange rate stability has been one of the most important objectives of European policy