Eyjafjallajökull

Eyjafjallajökull, the unpronounceable volcano that caused the biggest upset in air traffic history in the spring of 2010, is actually one of the smaller ice caps of Iceland, situated to the north of Skógar and to the west of Mýrdalsjökull. It peaks at 1,666 metres (5,466 ft) above sea level. In Icelandic, it’s name stands for "island-mountain-glacier".

The volcano has erupted relatively frequently since the last glacial period, most recently in 2010 and from 1821 to 1823. The volcano is a part of a chain of volcanoes stretching across Iceland. The Eyjafjallajökull volcano erupted in the years 920, 1612 and again from 1821 to 1823 when it caused a glacial lake outburst flood. As you might know, the volcano erupted twice in 2010 - on 20 March and in April/May. The March event forced a brief evacuation of around 500 local people, but the 14 April eruption was ten to twenty times more powerful and caused substantial disruption to air traffic across Europe.

The volcano continues to have several earthquakes daily, with Volcanologists watching the volcano closely.Only when activity has ceased for three months will it be considered dormant.
Text edited from Wikipedia.