Hekla 3 eruption

The Hekla 3 eruption (circa 1000 BCE) is thought to be the most severe eruption of Hekla during the Holocene.
Impact.
It threw more than 7 km3 of volcanic rock into the atmosphere. This would have caused a volcanic winter, cooling temperatures in the Northern Hemisphere for many years afterwards.
Claims.
Some claim that an eighteen-year span of global cooling that is recorded in Irish bog oaks can be blamed on Hekla-3.
Some Egyptologists have blamed Hekla-3 for famines under Ramesses III during the wider Bronze Age collapse.