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
Estonian kroon of 5, 10, 20 & 50 senti, as well as 1 kroon. The 1 kroon was struck in cupronickel, the others in aluminum-bronze. However, in 1997, nickel-plated steel 20 senti were introduced, followed by aluminum-bronze 1 kroon in 1998. 5 senti coins were not issued after 1994 but were still legal tender. The cupronickel 1 kroon coins from 1992, 1993 and 1995 were demonetized on 31 May 1998 because they were too similar in weight and composition to German one-mark coins, and new 1 kroon coins were issued. The 5 krooni coins were commemorative pieces and were rarely seen in