Eric XIV of Sweden in the context of "Estonia under Swedish rule"

The Northern Seven Years' War (also known as the Nordic Seven Years' War, the First Northern War, the Seven Years' War of the North or the Seven Years War in Scandinavia) was fought between the Kingdom of Sweden and a coalition of Denmark–Norway, Lübeck, and Poland–Lithuania between 1563 and 1570. The war was motivated by the dissatisfaction of King Frederick II of Denmark with the dissolution of the Kalmar Union, and the will of King Eric XIV of Sweden to break Denmark's dominating position. The fighting continued until both armies had been exhausted, and many men died. The resulting Treaty of Stettin was a stalemate, with neither party gaining any new territory.

Sigrid Eriksdotter of Sweden (15 October 1566 – 1633) was a Swedish princess, the legitimized daughter of King Eric XIV of Sweden and of his lover, later spouse and queen, Karin Månsdotter.

The early Vasa era is a period in Swedish history that lasted between 1523–1611. It began with the reconquest of Stockholm by Gustav Vasa and his men 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.