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.'" The name Britain descends from the Latin name for Britain, Britannia or Brittānia, the land of the Britons. Old French Bretaigne (whence also Modern French Bretagne) and Middle English Bretayne, Breteyne. The French form replaced the Old English Breoton, Breoten, Bryten, Breten (also Breoton-lond, Breten-lond). Britannia was used by the Romans from the 1st century BC for the British Isles taken together. It is derived from the travel writings of Pytheas around 320 BC, which described various islands in the North Atlantic as far north as Thule (probably Norway). The peoples of these islands of Prettanike were called the Πρεττανοί, Priteni or Pretani. Priteni is the source of the Welsh language term Prydain, Britain, which has the same source as the Goidelic term Cruithne used to refer to the early Brythonic-speaking inhabitants of Ireland. The latter were later called Picts or Caledonians by the Romans. Greek historians Diodorus of Sicily and Strabo preserved variants of Prettanike from the work of Greek explorer Pytheas of Massalia, who travelled from his home in Hellenistic southern Gaul to Britain in the 4th century BC. The term used by Pytheas may derive from a Celtic word meaning "the painted ones" or "the tattooed folk" in reference to body decorations. According to Strabo, Pytheas referred to Britain as Bretannikē, which is treated a feminine noun. Marcian of Heraclea, in his Periplus maris exteri, described the island group as (the Prettanic Isles). Derivation of Great The Greco-Egyptian scientist Ptolemy referred to the larger island as great Britain (μεγάλη Βρεττανία megale Brettania) and to Ireland as little Britain (μικρὰ Βρεττανία mikra Brettania) in his work Almagest (147–148 AD). In his later work, Geography (c. 150 AD), he gave the islands the names Alwion, Iwernia, and Mona (the Isle of Man), suggesting these may have been the names of the individual islands not known to him at the time of writing Almagest. The name Albion appears to have fallen out of use sometime after the Roman conquest of Britain, after which Britain became the more commonplace name for the island. After the Anglo-Saxon