The 1815 eruption of Mount Tambora was the most powerful volcanic eruption in human history (although some research shows Ilopango's eruption between the 5th and 6th century may have been bigger), with a Volcanic Explosivity Index (VEI) of 7. It is the most recently known VEI-7 event and the only unambiguously confirmed VEI-7 eruption since the Lake Taupo eruption in about 180 AD.