the first known written use of the word britain was an ancient greek transliteration of the original p-celtic term in a work on the travels and discoveries of pytheas that has not survived. the earliest existing records of the word are quotations of the periplus by later authors, such as those within strabo's "geographica", pliny's "natural history" and diodorus of sicily's "bibliotheca historica". pliny the elder (ad 23–79) in his "natural history" records of great britain: "its former name was albion; but at a later period, all the islands, of which we shall just now briefly make mention, were included under the name of 'britanniæ.'"