Pliny the Elder (b. Gaius Plinius Secundus, AD 23 – 79) was a Roman author, naturalist and natural philosopher, a naval and army commander of the early Roman Empire, and friend of the emperor Vespasian. 

Spending most of his spare time studying, writing, and investigating natural and geographic phenomena in the field, Pliny wrote the encyclopedic "Naturalis Historia" ("Natural History"), which became an editorial model for encyclopedias. His nephew, Pliny the Younger, wrote of him in a letter to the historian Tacitus: 

Pliny the Younger refers to Tacitus’s reliance upon his uncle's book, the "History of the German Wars". Pliny the Elder died in AD 79, while attempting the rescue, by ship, of a friend and his family, in Stabiae, from the eruption of Mount Vesuvius, which already had destroyed the cities of Pompeii and Herculaneum. The wind caused by the sixth and largest pyroclastic surge of the volcano’s eruption did not allow his ship to leave port, and Pliny probably died during that event. 

Pliny's dates are pinned to the eruption of Mount Vesuvius in AD 79 and a statement of his nephew that he died in his 56th year, which would put his birth 

Pliny was the son of an equestrian, Gaius Plinius Celer, and his wife, Marcella. Neither the younger nor the elder Pliny mention the names. Their ultimate source is a fragmentary inscription (CIL V 1 3442) found in a field in Verona and recorded by the 16th century Augustinian monk Onofrio Panvinio at Verona. The reading of the inscription depends on the reconstruction, but in all cases the names come through. Whether he was an augur and whether she was named Grania Marcella are less certain. Jean Hardouin presents a statement from an unknown source that he claims was ancient, that Pliny was from Verona and that his parents were Celer and Marcella. Hardouin also cites the conterraneity (see below) of Catullus.
what did the elder write?
Naturalis Historia