The peninsula as seen from the summit of Mount Athos (40°9′28″N 24°19′36″E), looking north-west
Athos in Greek mythology is the name of one of the Gigantes that challenged the Greek gods during the Gigantomachia. Athos threw a massive rock against Poseidon which fell in the Aegean sea and became the Mount Athos. According to another version of the story, Poseidon used the mountain to bury the defeated giant.
Homer mentions the mountain Athos in the Iliad (Rhapsody Ξ 219). Herodotus mentions the peninsula, then called Acte or Akte, telling us that Pelasgians from the island of Lemnos populated it and naming five cities thereon, Sane, Cleonae (Kleonai), Thyssos (Thyssus), Olophyxos (Olophyxis), Acrothoï (Akrothoön). (Herodotus, VII:22) Strabo also mentions the city of Dion (Dium) and that Acrothoï is near the crest. (Strabo, Geography, VII:33:1) Eretria also established colonies on Acte. At least another city was established in the Classical period: Acanthus (Akanthos). Some of these cities minted their own coins.
The peninsula was on the invasion route of Xerxes I, who spent three years excavating a channel across the isthmus to allow the passage of his invasion fleet in 483 BC. After the death of Alexander the Great, the architect Dinocrates (Deinokrates) proposed to carve the entire mountain into a statue of Alexander.
The history of the peninsula during latter ages is shrouded by the lack of historical accounts. Archaeologists have not been able to determine the exact location of the cities reported by Strabo. It is believed that they must have been deserted when Athos' new inhabitants, the monks, started arriving at some time before the 7th century AD.
According to the athonite tradition, the Blessed Virgin Mary was sailing accompanied by St John the Evangelist from Joppa to Cyprus to visit Lazarus. When the ship was blown off course to then pagan Athos it was forced to anchor near the port of Klement, close to the present monastery of Iviron. The Virgin walked ashore and, overwhelmed by the wonderful and wild natural beauty of the mountain, she blessed it and asked her Son for it to be her garden. A voice was heard saying "Let this place be your inheritance and your garden, a paradise and a haven of salvation for those seeking to be saved". From that moment the mountain was consecrated as the garden of the Mother of God and was out of bounds to all other women.
Historical documents on ancient Mount Athos history are very few. It is certain that monks have been there since the 4th century, and possibly since the 3rd. During Constantine I's reign (324–337) both Christians and pagans were living there. During the reign of Julian the Apostate (361–363), the churches of Mount Athos were destroyed, and Christians hid in the woods and inaccessible places. Later, during Theodosius I's reign (383–395), the pagan temples were destroyed. The lexicographer Hesychius of Alexandria states that in the 5th century there was still a temple and a statue of "Zeus Athonite". After the Islamic conquest of Egypt in the 7th century, many orthodox monks from the Egyptian desert tried to find another calm place; some of them came to the Athos peninsula. An ancient document states that monks "...built huts of wood with roofs of straw (...) and by collecting fruit from the wild trees were providing themselves improvised meals..."
Byzantine era: the first monasteries
The chroniclers Theophanes the Confessor (end of 8th century) and Georgios Kedrenos (11th century) wrote that the 726 eruption of the Thera volcano was visible from Mount Athos, proving that it was inhabited at the time. The historian Genesios recorded that monks from Athos participated at the 7th Ecumenical Council of Nicaea of 787. Around 860, the famous monk Efthymios the Younger came to Athos and a number of monk-huts ("skete of Saint Basil") were created around his habitation, possibly near Krya Near. During the reign of emperor Basil I the Macedonian, the former Archbishop of Crete (and later of Thessaloniki) Basil the Confessor built a small monastery at the place of the modern harbour ("arsanas") of Hilandariou Monastery. Soon after this, a document of 883 states that a certain Ioannis Kolovos built a monastery at Megali Vigla.
On a chrysobull of emperor Basil I, dated 885, the Holy Mountain is proclaimed a place of monks, and no laymen or farmers or cattle-breeders are allowed to be settled there. The next year, in an imperial edict of emperor Leo VI the Wise we read about the "...so-called ancient seat of the council of gerondes (council of elders)...", meaning that there was already a kind of monks' administration and that it was already "ancient". In 887, some monks expostulate to the emperor Leo the Wise as the monastery of Kolovos is growing more and more and they lose their peace.
In 908, the existence of a Protos ("First monk") is documented, who is the "head" of the monastic community. In 943, the borders of the monastic state was precisely mapped while we know that Karyes is already the capital town and seat of the administration and has the name "Megali Mesi Lavra" (Big Central Assembly). In 956, a decree offered land of about 940,000 m2 (10,118,075.79 sq ft) to the Xiropotamou monastery, which means that this monastery was already quite big.
In 958, the monk Athanasios the Athonite arrived on Mount Athos. In 962, he builds the big central church of the "Protaton" in Karies. In the next year, with the support of his friend, Emperor Nicephorus Phocas, the monastery of Great Lavra was founded, still the largest and most prominent of the 20 monasteries existing today. It enjoyed the protection of the emperors of the Byzantine Empire during the following centuries and its wealth and possessions grew considerably. The Fourth Crusade in the 13th century brought new Roman Catholic overlords which forced the monks to complain and ask for the intervention of Pope Innocent III, until the restoration of the Byzantine Empire came. The peninsula was raided by Catalan mercenaries in the 14th century, a century that also saw the theological conflict over the hesychasm practised on Mount Athos and defended by Gregory Palamas.