The Early Vasa era is a period that in Swedish and Finnish history lasted between 1523–1611. It began with the reconquest of Stockholm by Gustav Vasa and his men from the Danes in 1523, which was triggered by the event known as the Stockholm Bloodbath in 1520, and then was followed up by Sweden's secession from the Kalmar Union, and continued with the reign of Gustav's sons Eric XIV, John III, John's son Sigismund, and finally Gustav's youngest son Charles IX. The era was followed by a period commonly referred to as the Swedish Empire, or Stormaktstiden in Swedish, which means "Era Of Great Power".
Gustav's reign was marked by internal political and religious reforms, including the Protestant Reformation, where he converted to Protestantism and seized Catholic Church property and wealth, and unification of the provinces. At the death of Gustav in 1560, he was succeeded by his eldest son Eric. Eric was intelligent and skilled, but was in a constant strain with his brother and other noblemen. He engaged in warfare against both Denmark, Russia and Poland, but suffered periods of insanity in 1567. In 1568 he was dethroned and succeeded by his brother John.
John stabilized the international situation and made peace. He also wanted to partially restore Roman Catholicism but the idea did not come through in the end.
At the death of John in 1592, his son Sigismund succeeded him. Sigismund was already ruler of the Polish–Lithuanian Commonwealth, through his mother, and he would rule Poland from 1587 to 1632. He set up a regency and continued to reside in Poland. On learning about the Uppsala Synod, that finally declared Sweden's Lutheran doctrines, he returned home to protest. He found that the Riksdag of the Estates had already dethroned him and replaced him by Gustav Vasa's youngest son, his uncle, Charles IX. A brief civil war ensued that Sigismund lost in 1598, where after he fled the country never to return.
Establishment of the Vasa dynasty
In 1520, Stockholm was taken by Christian II of Denmark and became the scene of the Stockholm Bloodbath. By 1521, Gustav Eriksson, a nobleman and relative of Sten Sture the Elder, managed to gather troops from Dalarna in north-west Sweden and help from Lübeck, with the purpose of defeating the Danes. In August 1521, his men elected him their monarch. The Swedish War of Liberation started, and would last until the capture of Stockholm, in June 1523. Gustav Vasa then consolidated his rule against claims from Denmark.
Tax reforms took place in 1538 and 1558, whereby multiple complex taxes on independent farmers were simplified and standardised throughout the district; tax assessments per farm were adjusted to reflect ability to pay. Crown tax revenues increased, but more importantly the new system was perceived as fairer and more acceptable. A war with Luebeck in 1535 resulted in the expulsion of the Hanseatic traders, who previously had had a monopoly of foreign trade. With its own businessmen in charge Sweden's economic strength grew rapidly, and by 1544 Gustavus had support from 60% of the farmlands in all of Sweden. Sweden now built the first modern army in Europe, supported by a sophisticated tax system and government bureaucracy. Gustavus proclaimed the Swedish crown hereditary in his family, the house of Vasa. It ruled Sweden (1523–1654) and Poland (1587–1668).
After Gustav's death, his oldest son Eric XIV ascended the throne. His regency was marked by Sweden's entrance into the Livonian War and the Northern Seven Years' War, and the mutual relation between his developing mental disorder and the opposition with the aristocracy, leading to the Sture Murders (1567) and the imprisonment of his brother John (III), who was married to Catherine Jagiellonica, the sister of Sigismund II Augustus of Poland. A magnates' uprising led by John led to Erik's deposition and the kingship of John, followed by the regency of John's son Sigismund. Sigismund however was not able to defend the throne against Gustav's youngest son Charles (IX)
Reformation
Shortly after seizing power in 1523, Gustav Vasa addressed the Pope in Rome with a request for the confirmation of Johannes Magnus as new archbishop of Sweden, in the place of Gustav Trolle who had been formally deposed by the Riksdag of the Estates due to his involvement with the Danes. The pope initially refused, but gave his approval a year later. Magnus then was in a position between the reformation friendly king and the Catholic bishops. He was sent on a diplomatic mission to Russia in 1526 while the king continued the reformation. Magnus travelled down to Rome and was consecrated in 1533, but never returned home.