Which volcanic eruption was the most powerful in Icelandic history?

The Laki eruption was a long fissure eruption that sent lava and gas across southern Iceland for about eight months. It was not the biggest explosive blast in terms of ash column, but its impact was enormous because of the huge volume of lava and sulfur gases. In Iceland, it caused widespread livestock deaths and famine; across Europe, it likely contributed to atmospheric haze and abnormal weather. Historical accounts describe serious health and environmental effects. Laki is one of the clearest examples of a lava fissure eruption with continental-scale consequences.