700s. The present-day territory of Sweden is inhabited by Suiones and Gothones, Germanic tribes at war with each other.
800. Swedish Vikings start exploring the seas, establishing colonies in western Russia and eastern Europe and developing commercial ties with Byzantium, the Khazar Khaganate, and the Arab Caliphate.
9TH CENTURY. Frankish Christian missionaries penetrate Sweden, which is slowly Christianized.
1150-1160. Under king Erik IX, Sweden invades Finland and forces Christianity on the conquered Finns. A feudal economy based on agriculture and trade develops.
1397. The Union of Kalmar unites the 3 Scandinavian kingdoms of Denmark, Norway, and Sweden under a single (Danish) monarch but constant wars follow between the Danes and Swedes.
1521. A rebellion of Swedes led by Gustav Vasa, later king Gustav I Vasa, overthrows Danish influence in most of Sweden, which becomes a hereditary monarchy that establishes Lutheranism as the state religion.
MID-1500s. Sweden enters a century-long period of military expansion, waging wars against Poland and Russia, and acquiring many territories around the Baltic, including Estonia, Karelia, Ingria, and Livonia.
1630. King Gustav II Adolph (Gustavus Adolphus II), considered the greatest Swedish king and a champion of Protestantism, leads Sweden in the Thirty Years' War.
1648. By the Peace of Westphalia ending the Thirty Years' War, Sweden acquires a large part of Pomerania, the island of Ruegen, Wismar, the sees (bishoprics) of Bremen and Verden, and other German lands. Sweden participates in German affairs and makes an alliance with France but is defeated by the Prussians in 1675.
1700-1721. In the Great Northern War, king Charles XII invades northwestern Russia and defeats the Poles, but the Swedes are finally routed and replaced by Russia as the dominant power in the region. Sweden loses much of its German territory and cedes Livonia, Estonia, Ingria, part of Karelia, and several important Baltic islands to Russia.
1718. A new constitution is adopted, rejecting absolute monarchy and vesting the legislative power in a parliament (Riksdag) composed of 4 estates (nobles, clergy, burghers, and peasants). The executive power becomes the domain of a "secret committee" of the first 3 estates.
1805. King Gustav IV Adolph joins the European coalition of Britain, Russia, and Austria against France, but Russia later unites with France's Napoleon and attacks Sweden, which is forced to cede Finland and the Aland Islands.
1810. To appease Napoleon, the Riksdag chooses Marshal Jean Bernadotte, one of Napoleon's generals, as crown prince, heir to Sweden's childless king. Bernadotte fights against Napoleon in 1813-14 and Denmark is forced to yield Norway to Sweden in exchange for the Swedish lands in Pomerania. In 1815, the union of Norway with Sweden is recognized by the European powers.
1818. Bernadotte succeeds to the throne as Charles XIV John, and Sweden makes considerable progress materially, politically, and culturally under his reign. An early capitalist economy develops.
1867-86. Nearly 500,000 Swedes emigrate to America because of rising unemployment.
1905. Norway secedes from Sweden, without opposition from the Riksdag.
EARLY 1900s. Sweden adopts much progressive social legislation, notably in factory laws, accident insurance, and pension funds for workers, and limitation of working hours for women and children. Major developments in industry turn Sweden into a technologically advanced economy.
1914. Sweden declares neutrality in World War I and joins an agreement to protect the common economic interests of the 3 Scandinavian countries.
1920. Sweden joins the League of Nations.
1920s-1930s. The Social Democratic Party becomes the leading force in Swedish politics. Socialist governments in the 1920s and 1930s enact significant social reforms.
1945. Having been neutral throughout World War II, Sweden joins the United Nations and maintains its neutral stance during the Cold War, refusing to join NATO in 1949 but trying to upgrade its armed forces adequately.
1950s-1970s. Postwar Social Democratic governments vastly expand the welfare state while developing a strong export-oriented market economy based on engineering and research.
1972. Swedish opposition to the Vietnam war voiced by popular Social Democratic prime minister Olof Palme arouses indignation in the U.S. as many young American war resisters are given political asylum in Sweden.
1991. Social Democrats decline in authority, although they remain the largest parliamentary party. Carl Bildt of the Moderate Party forms a coalition cabinet with the Center, Liberal, and Christian Democratic parties, stressing deregulation of the economy, privatization of state companies, cuts in government spending, including welfare, and removing restrictions on foreign companies in Sweden.
1994. Social Democrats return to power.
1995. Sweden enters the European Union as a full member.