The krona (plural: kronor; sign: kr; code: SEK) is the official currency of Sweden. Both the ISO code "SEK" and currency sign "kr" are in common use; the former precedes or follows the value, the latter usually follows it but, especially in the past, it sometimes preceded the value. In English, the currency is sometimes referred to as the Swedish crown, as krona literally means "crown" in Swedish. The Swedish krona was the ninth-most traded currency in the world by value in April 2016.

One krona is subdivided into 100 öre (singular; plural öre or ören, where the former is always used after a cardinal number, hence "50 öre", but otherwise the latter is often preferred in contemporary speech). However, all öre coins were discontinued from 30 September 2010. Goods can still be priced in öre, but all sums are rounded to the nearest krona when paying with cash. The word öre is ultimately derived from the Latin word for gold

The introduction of the krona, which replaced at par the riksdaler, was a result of the Scandinavian Monetary Union, which came into effect in 1876 and lasted until the beginning of World War I. The parties to the union were the Scandinavian countries, where the name was krona in Sweden and krone in Denmark and Norway, which in English literally means "crown". The three currencies were on the gold standard, with the krona/krone defined as 1⁄2480 of a kilogram of pure gold.

After dissolution of the monetary union in August 1914, Sweden, Denmark, and Norway all decided to keep the names of their respective and now separate currencies.

In 1874, notes were introduced by the Riksbank in denominations of 1 krona and 5, 10, 50, 100 and 1,000 kronor. The 1-krona was only initially issued for two years, although it reappeared between 1914 and 1920. In 1939 and 1958, 10,000-krona notes were issued.

Production of the 5 kronor note ceased in 1981, although a coin had been issued since 1972. With the introduction of a 10-krona coin in 1991, production of 10-krona notes ceased and a 20 kronor note was introduced.

All remaining one-krona banknotes became invalid after 31 December 1987. All remaining five-krona and ten-krona banknotes became invalid after 31 December 1998.

Gustav I, born Gustav Eriksson of the Vasa noble family and later known as Gustav Vasa (12 May 1496 – 29 September 1560), was King of Sweden from 1523 until his death in 1560, previously self-recognised Protector of the Realm (Riksföreståndare) from 1521, during the ongoing Swedish War of Liberation against King Christian II of Denmark, Norway and Sweden. Gustav rose to lead the rebel movement following the Stockholm Bloodbath, where his father was executed. Gustav's election as king on 6 June 1523 and his triumphant entry into Stockholm eleven days later marked Sweden's final secession from the Kalmar Union.

As king, Gustav proved an energetic administrator with a ruthless streak not inferior to his predecessor's, brutally suppressing subsequent uprisings (three in Dalarna – which had once been the first region to support his claim to the throne – one in Västergötland, and one in Småland). He worked to raise taxes and bring about a Reformation in Sweden, replacing the prerogatives of local landowners, noblemen and clergy with centrally appointed governors and bishops. His 37-year rule, which was the longest of a mature Swedish king to that date (subsequently passed by Gustav V and Carl XVI Gustav) saw a complete break with not only the Danish - Norwegian supremacy but also the Roman Catholic Church, whose assets were nationalised, with the Lutheran Church of Sweden established under his personal control. He became the first truly autocratic native Swedish sovereign and was a skilled bureaucrat and propagandist, with tales of his largely fictitious adventures during the liberation struggle still widespread to this day. In 1544, he abolished Medieval Sweden's elective monarchy and replaced it with a hereditary monarchy under the House of Vasa, which held the Swedish throne until 1654. Thus, three of his sons, Eric XIV, John III and Charles IX, all held the kingship at different points.

Gustav I has subsequently been labelled the founder of modern Sweden, and the "father of the nation". Gustav liked to compare himself to Moses, whom he believed to have also liberated his people and established a sovereign state. As a person, Gustav was known for ruthless methods and a bad temper, but also a fondness for music and had a certain sly wit and ability to outmaneuver and annihilate his opponents. He founded one of the now oldest orchestras of the world, the Kungliga Hovkapellet (Royal Court Orchestra). Royal housekeeping accounts from 1526 mention twelve musicians including wind players and a timpanist but no string players. Today the Kungliga Hovkapellet is the orchestra of the Royal Swedish Opera.