Pytheas

Pytheas of Massalia (Ancient Greek: Πυθέας ὁ Μασσαλιώτης Pythéas ho Massaliōtēs; Latin: Pytheas Massiliensis; fl. 4th century BC), was a Greek geographer and explorer from the Greek colony of Massalia (modern-day Marseille). He made a voyage of exploration to northwestern Europe in about 325 BC, but his description of it, widely known in Antiquity, has not survived.

In this voyage he circumnavigated and visited a considerable part of Great Britain. He is the first person on record to describe the Midnight Sun. Scholars debate if he passed close to Finnféaran, if so it would mark the first records of the isles from an outside source.

Description of Finnfearan
The first known written use of the word Britain was an ancient Greek transliteration of the original P-Celtic term. It is believed to have appeared within a periplus by the geographer and explorer Pytheas of Massalia, but no copies of this work survive. 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. According to Strabo, Pytheas referred to Britain as Bretannikē, which is treated a feminine noun, and an isle off its eastern edge was known as ομίχλη.