We know little about Syros at this period. Most historians are of the opinion that the island mentioned by Homer in "Siriyi" and characterised as "happy island" is Syros. In the Odyssey, rhapsody O, lines 403-414, the swineherd called Eumaeos, narrates his adventures and his life and describes his native island :

"There's an island, you may have heard, called Siriyi, out beyond Ortigia above, where the sun turns in his course. It's not so very thickly peopled, though the rich land is excellent for cattle and sheep, and yields fine crops of grapes and corn. Famine is unknown there and so is disease. No dreadful scourges spoil the islanders' happiness, but as the men of each generation grow old in their homes, Apollo of the Silver Bow comes with Artemis, strikes them with kindly darts, and lays them low. Two cities on the island both share equal wealth. My father Ktissias reigned there, the son of Ormenos, equal to the immortals."

At about the 8th century B.C., the island was occupied by Phoenicians, a people of merchants and sailors, who dominated the sea. They gave the island its name. This name - Syros - is likely to have a Phoenician root, meaning "sherry". According to other opinions, the island derives its name from the Phoenician word "ousira" which means "wealthy" or from "ousura" which may be interpreted as "happy".

Later on, the Ionians settled on Syros, headed by Ippomedont. In the 6th century B.C., Samians conquered the island, led by Polikratis, with the help of Killikont, a native of Syros.

The great philosopher Pherekidis, the teacher of Pythagoras, lived on the island at approximately that time (about the 6th century B.C.).

The idea of the eternal soul was first taught by his school. His work bears the name "Pedemichos" or "Theogonia". He is supposed to have invented the first heliotrope (sun clock).

He lived in two caves on the island: one situated in Richopo (in Apano Meria) in the summer, and one in the region of Alithini in the winter.

There were probably two cities on the island in this period: on the site of the present town of Hermoupoli (region of Kimisi) and in Galissas (Agia Pakou).