There was "Laki: How A Volcano Swallowed Europe" whose effects on weather and agriculture more than likely contributed to the early unrest that led to the French Revolution, see this morning's Food Supply: "The Great Fear".
And Katla which led to some very chilly years in North America and Bárðarbunga dude.
And here's more at The Guardian, April 10:
Reykjanes peninsula’s last active period started in 10th century and lasted 300 years
Volcanic activity is escalating in a region of Iceland that has not erupted for 800 years, with scientists warning it could cause disruption for centuries to come.
Since 21 January, the Reykjanes peninsula south-west of Iceland’s capital, Reykjavik, has experienced more than 8,000 earthquakes and about 10cm of land uplift due to magma intrusions underground.
“It seems that after being relatively inactive for many centuries, this region is waking up,” said Dave McGarvie, a volcanologist at Lancaster University.
Situated close to the town of Grindavík and the popular Blue Lagoon tourist attraction, and only nine miles (15km) from Iceland’s international airport, the region last erupted about 800 years ago (though there have been more recent eruptions offshore). Geological evidence shows the area is fed by five volcanic systems, which seem to come to life in a coordinated way roughly every 1,000 years.
The last period of volcanic activity on the peninsula began in the 10th century and continued until the 13th. Unlike typical Icelandic volcanoes, which tend to wake for a few years and then die down, when this region gets going it appears to splutter on and off for up to 300 years, producing eruptive episodes (locally known as “fires”) lasting a few decades. Long thin cracks known as fissures extend up to five miles (8km), producing fountains of lava, usually without large amounts of ash or explosive activity....MUCH MORE
