People have been living in Scandinavia since before the Neolithic period, with the region marked by a distinctive “Battle Axe Culture,” who take their name from the carved stone axes found in period graves of high-status individuals. Small bands and settlements made up the preponderance of settlements, and it was a pagan realm of Viking raiders through the end of the Western Roman Empire (Scandinavian tribes appear to have been part of the period of migration) and up through the start of the medieval period.

Christian missionaries visited during the 9th Century, first by St. Ansgar, but Christianity as a whole was not widely established until the 11th or 12th Centuries, during the time in which the Vikings were at the height of their activity. During this time, there was a gradual change from the traditional Viking way of life towards more of a feudal model, and in 1280, King Magnus Ladulas established a true feudal model of governance in Sweden, with an established nobility owing service to their liege.

This feudal system and consolidated rule of the monarch continued. Sweden's famous “Tre Kronor” heraldry—three golden crowns on a field of blue—was first used in the early 1300s, and is still one of the recognizable symbols of the country. In 1389, the crowns of Denmark, Sweden, and Norway were all held in personal union by the Danish Queen Margareta. The resultant Kalmar Union of 1397 united all three lands under the monarch, but the unification was not peaceful in practice.

Jealousies and internecine strife escalated between Danish and Swedish, factions, drawing in German principalities and the Hanseatic League. The Swedes attempted to gain greater autonomy for themselves over decades, and the matter came to a head when Danish King Kristian II executed a number of prominent people in Stockholm in 1521. This provoked a general revolution, led by the Swedish nobleman Gustav Vasa. He was crowned King Gustav I Vasa of Sweden by the nobility, successfully fended off Danish efforts to remove him, and ruthlessly crushed any opposition to his rule, and for this is generally seen as the father of the modern state.

Sweden was an early convert to nascent Protestantism under the direction of Gustav I, occurring at about the same time as Henry VIII's conversion in England (and under much the same set of circumstances, both being the result of long-simmering conflicts between the king and the pope). Sweden would continue to be a bastion of Lutheranism during the centuries that followed. King Gustav II Adolphus Vasa was one of Sweden's most famous kings, a redoubtable warrior on the Protestant side during the Thirty Years' War, who left Sweden the first-rate power in Northern Europe for the next century. Gustavus Adolphus died at the Battle of Lützen in 1632, and reign passed to his only child, Kristina (see her section for her life.)

However, Sweden's control of the Baltic region declined after the Great Northern War in the early 1700s, losing prominence to Russia and its allies—including the Danish-Norwegians. During the Napoleonic Era, Sweden lost the territory of modern Finland to Russia, and was pressed into another union with Norway in 1810 through the French Marshal Jean Baptiste Bernadotte—placed there by Napoleon as part of his reordering of Europe. The new king, who had been a Parisian Jacobin firebrand as a young man, was rumored to have had “Death to Kings” tattooed on his arm.

Eventually, the union with Norway was dissolved at the start of the 20th Century, to the relief of everyone. Rapid industrialization defined the early part of the 20th Century. The first Nobel Prizes were awarded in 1901, the gift of the chemist and entrepreneur Alfred Nobel, who had come to desire to remembered as something other than an inventor of more efficient ways for people to kill each other.

Sweden had an unbroken policy of neutrality in European wars since the middle of the Napoleonic period. The morality of this policy during World War II was controversial at the time and which is still hotly debated by scholars today. But in the years that followed, Sweden was an ardent supporter of the international order, seeing it as a way to prevent global wars and other political catastrophes.

Sweden's long history has been one of iteration and reform of its political systems and governance, and it has succeeded in creating a stable, orderly, egalitarian society, with a high degree of equality for all its citizens. Having renounced military adventurism for two centuries, it has used those resources to develop the nation, and leads many rankings of quality of life. Sweden has been at the forefront of political solutions for international problems through the United Nations, and the Swedish economist and politician Dag Hammarskjöld served as the second Secretary General of that body and remains one of the best-regarded statesmen of the Twentieth Century. As the Twenty-First Century progresses, the nation continues to endorse its egalitarian principles, as applied to all the nations of the world—and thus Sweden enhances its reputation as a willing arbiter between parties seeking to establish a lasting peace.