Some scholars believe that the first attempts to penetrate the Arctic Circle can be traced to ancient Greece and the sailor Pytheas, a contemporary of Aristotle and Alexander the Great, who, in c. 325 BC, attempted to find the source of the tin that would sporadically reach the Greek colony of Massilia (now Marseille) on the Mediterranean coast. Sailing past the Pillars of Hercules, he reached Brittany and then Cornwall, eventually circumnavigating the British Isles. From the local population, he heard news of the mysterious land of Thule, even farther to the north. After six days of sailing, he reached land at the edge of a frozen sea (described by him as "curdled"), and described what is believed to be the aurora and the midnight sun. Some historians claim that this new land of Thule was either the Norwegian coast or the Shetland Islands based on his descriptions and the trade routes of early British sailors. While no one knows exactly how far Pytheas sailed, he may have crossed the Arctic Circle. Nevertheless, his tales were regarded as fantasy by later Greek and Roman authorities, such as the geographer Strabo.
The first Viking to sight Iceland was Gardar Svavarsson, who lost his route due to harsh conditions when sailing from Norway to the Faroe Islands. This quickly led to a wave of colonization. Not all the settlers were successful however in the attempts to reach the island. In the 10th century, Gunnbjörn Ulfsson got lost in a storm and ended up within sight of the Greenland coast. His report spurred Erik the Red, an outlawed chieftain, to establish a settlement there in 985. While they flourished initially, these settlements eventually foundered due to changing climatic conditions (see Little Ice Age). They are believed to have survived until around 1450.
Greenland's early settlers sailed westward, in search of better pasturage and hunting grounds. Modern scholars debate the precise location of the new lands of Vinland, Markland, and Helluland that they discovered.
The Scandinavian peoples also pushed farther north into their own peninsula by land and by sea. As early as 880, the Viking Ohthere of Hålogaland rounded the Scandinavian Peninsula and sailed to the Kola Peninsula and the White Sea. The Pechenga Monastery on the north of Kola Peninsula was founded by Russian monks in 1533; from their base at Kola, the Pomors explored the Barents Region, Spitsbergen, and Novaya Zemlya—all of which are in the Arctic Circle. They also explored north by boat, discovering the Northern Sea Route, as well as penetrating to the trans-Ural areas of northern Siberia. They then founded the settlement of Mangazeya east of the Yamal Peninsula in the early 16th century. In 1648 the Cossack Semyon Dezhnyov opened the now famous Bering Strait between America and Asia.
Russian settlers and traders on the coasts of the White Sea, the Pomors, had been exploring parts of the northeast passage as early as the 11th century. By the 17th century they established a continuous sea route from Arkhangelsk as far east as the mouth of Yenisey. This route, known as Mangazeya seaway, after its eastern terminus, the trade depot of Mangazeya, was an early precursor to the Northern Sea Route.