had settled in Scotland and Ireland and intermarried with Gaelic-speaking people". Genetic evidence suggests that approximately 62% of the Icelandic maternal gene pool is derived from Ireland and Scotland, which is much higher than other Scandinavian countries, although comparable to the Faroese, while 37% is of Nordic origin. About 20–25% of the Icelandic paternal gene pool is of Gaelic origin, with the rest being Nordic. The Icelandic Age of Settlement () is considered to have lasted from 874 to 930, at which point most of the island had been claimed and the (), the assembly of the Icelandic Commonwealth, was founded at Þingvellir. Hardship and conflict In 930, on the Þingvellir () plain near Reykjavík, the chieftains and their families met and established the Alþingi, Iceland's first national assembly. However, the Alþingi lacked the power to enforce the laws it made. In 1262, struggles between rival chieftains left Iceland so divided that King Haakon IV of Norway was asked to step in as a final arbitrator for all disputes, as part of the Old Covenant. This is known as the Age of the Sturlungs. Iceland was under Norwegian leadership until 1380, when the Royal House of Norway died out. At this point, both Iceland and Norway came under the control of the Danish Crown. With the introduction of absolute monarchy in Denmark, the Icelanders relinquished their autonomy to the crown, including the right to initiate and consent to legislation. This meant a loss of independence for Iceland, which led to nearly 300 years of decline: perhaps largely because Denmark and its Crown did not consider Iceland to be a colony to be supported and assisted. In particular, the lack of help in defense led to constant raids by marauding pirates along the Icelandic coasts. Unlike Norway, Denmark did not need Iceland's fish and homespun wool. This created a dramatic deficit in Iceland's trade, and no new ships were built as a result. In 1602, Iceland was forbidden to trade with other countries by order of the Danish Government, and in the 18th century climatic conditions had reached an all-time low since Settlement. In 1783–84, Laki, a volcanic fissure in the south of the island, erupted. The eruption produced about 15 km3 (3.6 mi3) of basalt lava, and the total volume of tephra emitted was 0.91 km3. The aerosols that built up caused a cooling effect in the Northern Hemisphere. The