Iceland was first permanently settled in 874 CE when Ingólfur Arnarson, a Norwegian chieftain fleeing conflict in his homeland, built a farm at the site of present-day Reykjavík. Archaeological evidence from Aðalstræti and excavations beneath the Old Harbour shows continuous occupation from this date. The Landnámabók (Book of Settlements), compiled in the 12th century from oral traditions, records approximately 400 principal settlers who arrived between 870 and 930 CE, most from western Norway but including Norse colonists from Ireland and Scotland who brought Celtic slaves and wives. Genetic studies published in 2018 by deCODE genetics indicate modern Icelanders derive roughly 70-75% of their male lineage from Scandinavia and 60-65% of their female lineage from the British Isles, reflecting this pattern of Norse men and Celtic women. The settlement period ended around 930 CE when available land was claimed.
The settlers established the Alþingi (Althing) at Þingvellir in 930 CE, creating what scholars recognize as one of the world's oldest existing parliamentary institutions. The assembly met annually for two weeks in June at the dramatic geological rift where the North American and Eurasian tectonic plates diverge. Representatives from each region gathered to legislate, adjudicate disputes, and conduct political business. Iceland had no executive branch or king during this Commonwealth period. The Lögrétta, a legislative council of 36 chieftains, passed laws that the Lögsögumaður (Law Speaker) recited from memory at the Law Rock. This system relied on prosecution by individuals rather than a state authority, since no centralized enforcement mechanism existed. Blood feuds and revenge killings formed the substance of the Icelandic sagas, written two centuries later but describing events from this period.
Christianity reached Iceland through political calculation rather than conquest. In the year 1000, the Alþingi faced a crisis as Christians and pagans threatened to split the society. Þorgeir Ljósvetningagoði, the Law Speaker and a pagan, meditated under a cloak for a day and night at Þingvellir, then declared that all Icelanders would adopt Christianity to preserve unity, though private pagan worship would be tolerated. According to tradition recorded in Kristni saga and Íslendingabók, Þorgeir threw his pagan idols into the waterfall Goðafoss on his journey home. The decision was pragmatic, acknowledging that Norway's Christian king Olaf Tryggvason had threatened trade embargoes and worse. Two episcopal sees were established, at Skálholt in 1056 and Hólar in 1106. These bishops became major landholders and political powers, with Skálholt controlling much of the south and Hólar administering the north.
The Commonwealth collapsed during the Sturlungaöld (Sturlung Age) of 1220 to 1264, a period of escalating violence among powerful families competing for wealth and control. The sagas documenting this era, particularly Sturlunga saga, record systematic feuding, assassinations, and small-scale warfare that destabilized the society. Norwegian king Hákon Hákonarson exploited these divisions by offering patronage to Icelandic chieftains who agreed to become his vassals. Gissur Þorvaldsson, who had killed the poet and chieftain Snorri Sturluson in 1241 at the Norwegian king's bidding, led the faction that brought Iceland under Norwegian rule. Between 1262 and 1264, each district assembly swore allegiance to Norway in exchange for the Gamli sáttmáli (Old Covenant), which promised six ships annually from Norway carrying essential goods. Iceland would remain under foreign rule for the next 678 years.
When Norway entered the Kalmar Union with Denmark and Sweden in 1397, Iceland passed to Danish control, which became permanent after Sweden's departure from the union in 1523. The Danish crown monopolized Icelandic trade from 1602 to 1787, restricting all commerce to specific Danish merchants in designated ports. This system impoverished Iceland, as merchants charged inflated prices for imports and paid minimal amounts for Icelandic exports of fish, wool, and tallow. The monopoly coincided with climatic deterioration during the Little Ice Age, when advancing glaciers destroyed farms and sea ice blocked fishing grounds for months. Iceland's population, approximately 60,000 in 1700, fell to perhaps 40,000 by 1800.
The eruption of Lakagígar (Laki craters) in 1783-1784 produced the worst disaster in Iceland's recorded history. The fissure eruption released an estimated 14 cubic kilometers of basalt lava and 122 million tons of sulfur dioxide over eight months. The resulting haze poisoned grazing land across Iceland, killing approximately 50-80% of sheep and horses and 50% of cattle. The Móðuharðindin (Mist Hardships) famine that followed killed roughly 10,000 people, approximately 20-25% of Iceland's population. Danish officials seriously considered evacuating the surviving population to Denmark's Jutland peninsula. Pastor Jón Steingrímsson's "fire sermon" at Kirkjubæjarklaustur on July 20, 1783, supposedly halted the advancing lava front before it destroyed the church, though geological evidence suggests the flow had already slowed. The eruption's sulfate aerosols disrupted climate across the Northern Hemisphere, with documented effects on harvest failures in Europe.
Icelandic nationalism emerged in the 19th century, led by Jón Sigurðsson, a philologist and politician born in the Westfjords in 1811. Working from Copenhagen, where he studied and worked at the Arnamagnæan Manuscript Collection, Jón led the movement for restoration of the Alþingi and eventual independence. Denmark restored the Alþingi as an advisory body in 1843, meeting initially in Reykjavík. Iceland gained control over domestic affairs in 1874, when Christian IX of Denmark visited Reykjavík to mark the thousandth anniversary of settlement. Jón Sigurðsson died in 1879 in Copenhagen, seventeen years before Denmark granted Iceland home rule in 1904 and forty-five years before full sovereignty in 1918. His birthday, June 17, became Iceland's Independence Day when full independence was achieved.
The Act of Union between Denmark and Iceland, signed December 1, 1918, created the Kingdom of Iceland as a sovereign state sharing a monarch with Denmark but controlling its own affairs. Icelanders voted to end this arrangement while Denmark was occupied by Nazi Germany. A referendum held May 20-23, 1944, produced 97% approval for complete independence and 95% support for a republican constitution. Iceland declared full independence on June 17, 1944, establishing a republic with Sveinn Björnsson as the first president. The choice to break with Denmark during its occupation was controversial, but Iceland had been militarily occupied by British forces since May 10, 1940, after Denmark fell, and by American forces after July 1941, making its separate status a practical reality.
Iceland's population in 2024 stands at approximately 395,000, with roughly 230,000 in the Greater Reykjavík area encompassing Reykjavík, Kópavogur, Hafnarfjörður, Garðabær, and Mosfellsbær. Akureyri, the largest town outside the capital region, has approximately 20,000 residents. The total population in 1900 was 78,000, reaching 100,000 around 1920, 200,000 in 1966, and 300,000 in 2009. The population density of roughly 3.5 persons per square kilometer makes Iceland the most sparsely populated country in Europe. Approximately 14% of the current population is foreign-born, with the largest groups from Poland (estimated 20,000), Lithuania (approximately 4,000), and the Philippines (approximately 3,000), reflecting labor immigration beginning in the early 2000s construction boom.
Icelandic remains the national language, belonging to the North Germanic branch and most closely related to Faroese and extinct Norse dialects. The language has changed remarkably little since medieval times, allowing modern Icelanders to read the 13th-century sagas with less difficulty than English speakers face with Chaucer. This linguistic conservatism stems from Iceland's isolation and deliberate language planning by the Icelandic Language Committee, which has coined Icelandic neologisms rather than adopting loanwords.