Old Kingdom of Norway

State · 866–1401 CE · at its largest around 1333 CE

The Norwegian kingdom from its unification, traditionally credited to Harald Fairhair, through the Middle Ages, until it entered the Kalmar Union with Denmark and Sweden.

On its lands while it lasted

Norse settlement of Iceland (c. 874 CE): Norse settlers, mainly from western Norway, colonised Iceland from about 874; tradition names Ingólfr Arnarson, who settled at Reykjavík, as the first permanent settler.
Pskov (903 CE): Capital of Pskov Republic (1348–1510).
First Althing (930 CE): Iceland's general assembly first met at Þingvellir in 930, making it one of the oldest parliaments in the world.
Thingvellir National Park (c. 936 CE): Capital of Icelandic Commonwealth (936–1262).
Stockholm (c. 980 CE): Capital of Kingdom of Sweden (980–today), Kalmar Union (1436–1523), Swedish Empire (1612–1721), and 1 more.
Battle of Stiklestad (1030 CE): King Olaf II of Norway was killed fighting his rebellious subjects; he was soon venerated as Saint Olaf, patron saint of Norway.
Oslo (1048 CE): Capital of Kalmar Union (1402–1523), Denmark-Norway (1536–1814), Kingdom of Norway (1814–today).
Lewis chessmen (c. 1150 CE): A set of 12th-century chess pieces carved mostly from walrus ivory, probably in Norway, and found on the Isle of Lewis in 1831. They are held by the British Museum and the National Museum of Scotland.
Prose Edda (c. 1220 CE): Old Norse handbook of poetics and mythology written by Snorri Sturluson in Iceland, a key source for Norse mythology.
Battle on the Ice (1242 CE): Forces of Novgorod under Alexander Nevsky defeated the knights of the Livonian Order on frozen Lake Peipus.