The Swedish Empire (, "the Era of Great Power") was the period in Swedish history spanning much of the 17th and early 18th centuries during which Sweden became a European great power that exercised territorial control over much of the Baltic region. The beginning of the period is usually taken as the reign of Gustavus Adolphus, who ascended the throne in 1611, and its end as the loss of territories in 1721 following the Great Northern War.
After the death of Gustavus Adolphus in 1632, the empire was controlled for lengthy periods by part of the high nobility, such as the Oxenstierna family, acting as regents for minor monarchs. The interests of the high nobility contrasted with the uniformity policy (i.e., upholding the traditional equality in status of the Swedish estates favoured by the kings and peasantry). In territories acquired during the periods of de facto noble rule, serfdom was not abolished, and there was also a trend to set up respective estates in Sweden proper. The Great Reduction of 1680 put an end to these efforts of the nobility and required them to return estates once gained from the crown to the king. Serfdom, however, remained in force in the dominions acquired in the Holy Roman Empire and in Swedish Estonia, where a consequent application of the uniformity policy was hindered by the treaties by which they were gained.
After its victories in the Thirty Years' War, Sweden reached the height of its power during the Second Northern War, when its primary adversary, Denmark–Norway, was neutralized by the Treaty of Roskilde in 1658. However, in the further course of this war, as well as in the subsequent Scanian War, Sweden was able to maintain its empire only with the support of its closest ally, France. Charles XI of Sweden consolidated the empire. But a decline began with his son, Charles XII. After initial Swedish victories, Charles secured the empire for some time in the Peace of Travendal (1700) and the Treaty of Altranstädt (1706), before the disaster that followed the king's war in Russia. The Russian victory at the Battle of Poltava put an end to Sweden's eastbound expansion, and by the time of Charles XII's death in 1718 only a much-weakened and far smaller territory remained. The last traces of occupied continental territory vanished during the Napoleonic Wars, and Finland went to Russia in 1809, with Sweden's role as a great power vanishing as well.
Sweden is the only Nordic country to have ever reached the status of a military great power.
History
Emergence as a great power
Sweden emerged as a great European power under Axel Oxenstierna and King Gustavus Adolphus. As a result of acquiring territories seized from Russia and the Polish–Lithuanian Commonwealth, as well as its involvement in the Thirty Years' War, Sweden found itself transformed into the leader of Protestantism.
During the Thirty Years' War, Sweden managed to conquer approximately half of the member states of the Holy Roman Empire. The fortunes of war would shift back and forth several times. After its defeat in the Battle of Nördlingen (1634), confidence in Sweden among the Swedish-controlled German states was damaged, and several of the provinces refused further Swedish military support, leaving Sweden with only a couple of northern German provinces. After France intervened on the same side as Sweden, fortunes shifted again. As the war continued, the civilian and military death toll grew, and when it was over, it had led to severe depopulation in the German states. Although exact population estimates do not exist, historians estimate that the population of the Holy Roman Empire fell by one-third as a result of the war.
Sweden founded overseas colonies, principally in the New World. New Sweden was founded in the valley of the Delaware River in 1638, and Sweden later laid claim to a number of Caribbean islands. A string of Swedish forts and trading posts was constructed along the coast of West Africa as well, but these were not designed for Swedish settlers.
Peace of Westphalia
At the conclusion of the Thirty Years' War, the Peace of Westphalia in 1648 granted Sweden territories as war reparations. Sweden demanded Silesia, Pomerania (which had been in its possession since the Treaty of Stettin (1630), and a war indemnity of 20,000,000 Riksdaler.