I think most volcanologists would agree that their science began with the detailed description of the AD 79 eruption of Vesuvius by Pliny the Younger. He described the earthquakes before the eruption, the eruption column, air fall, the effects of the eruption on people, pyroclastic flows, and even tsunami.

Even the foundational text "Volcanoes" by Peter Francis contains several direct passages from Pliny the Younger!

Studying Volcanoes / Volcanology