Short answers, pulled from the story.
Diodorus Siculus was an ancient Greek historian from Agyrium in Sicily, known today as Agira. He flourished in the first century BC and composed his major work between 60 and 30 BC. Jerome, writing under the year 49 BC, recorded that Diodorus became illustrious as a writer of Greek history.
The Bibliotheca historica, or Historical Library, is a universal history in forty books written by Diodorus Siculus. It covers mythic history through to events around 60 BC, structured in three parts: mythic and geographical accounts of the ancient world, the period from the Trojan War to Alexander the Great, and the era of Alexander's successors.
Fifteen of the original forty books survive intact: books one through five and books eleven through twenty. Fragments of the remaining twenty-five lost books are preserved in the writings of Photius and the Excerpts of Constantine Porphyrogenitus.
Diodorus Siculus was born in Agyrium in Sicily, a town now called Agira. He states this himself in his work, and a Greek inscription found at Agyrium, catalogued as Inscriptiones Graecae XIV, 588, marks the tomb of one Diodorus, the son of Apollonius, which his translator Charles Henry Oldfather noted as a striking coincidence.
Diodorus drew on a wide range of earlier Greek historians, including Hecataeus of Abdera, Ctesias of Cnidus, Ephorus, Theopompus, Hieronymus of Cardia, Duris of Samos, Diyllus, Philistus, Timaeus, Polybius, and Posidonius. He chose the title Bibliotheca, meaning library, to acknowledge that his work was a composite assembled from many sources.
Diodorus named his work Bibliotheca, the Greek word for library, to acknowledge that he was drawing on the work of many other authors rather than writing an original account. The title was an explicit statement of his method: synthesis and preservation of earlier scholarship into a single universal history.