Pliny the Elder was a Roman author, naturalist, and naval and army commander who lived in the first century AD. He is known for his encyclopedic work Naturalis Historia, which covered topics such as astronomy, geography, medicine, and zoology and became a major source for the natural history of the ancient world. Pliny the Elder died in 79 AD while attempting to rescue survivors from the eruption of Mount Vesuvius that destroyed the cities of Pompeii and Herculaneum.