The ʻAilaʻau eruption is considered the longest memorable eruption of Kilauea. (Before Pele there was ʻAilaʻau (Ai means the ‘one who eats or devours.’ Laʻau means ‘tree’ or a ‘forest.’) ʻAilaʻau was, therefore, the fire-god devouring forests. When Pele came she took over as fire goddess, ʻAilaʻau left.)
The ʻAilaʻau eruption took place from a vent area just east of Kilauea Iki. The eruption probably lasted about 50-years, from about 1420 to 1470 AD. Reminders of past eruptions are lava tubes. One such, as a result of the ʻAilaʻau eruption is Kazumura Cave – it has been called the longest (over 40-miles) and (to some) deepest lava tube in the world and the deepest cave in the US.