Pliny the Younger wrote two letters to the historian Tacitus describing the eruption of Vesuvius in 79 AD, and they are the only eyewitness account of one of the most significant natural disasters in recorded history. Pliny was seventeen years old when the eruption occurred. He watched from Misenum, across the Bay of Naples, as the cloud rose from the mountain. His uncle, Pliny the Elder — the naturalist and admiral who commanded the fleet at Misenum — sailed toward the eruption and died in it. The younger Pliny stayed behind, survived, and thirty years later wrote the letters that documented what he had seen with a clarity and precision that would have done credit to a trained scientist.