In archaic times the city was an unimportant settlement at the southern periphery of the
Cyclades. It was founded by
Doric colonists from
Sparta, who recognized the strategic value of its location on a rocky ridge.
Herodotus and
Pausanias give accounts of the mythical ruler,
Theras, a descendant of the
Phoenician ruler
Cadmus and son of the king of
Thebes,
Autesion, who ruled over Sparta and
Laconia on behalf of his underage nephews
Eurysthenes and
Procles. After they came of age he founded a new settlement on the island of Kalliste (old Greek: Καλλίστῃ), which was subsequently named Thera after him (modern Greek: Thira, Θήρα). This name was also given to the city, of which there is archaeological evidence dating from the 9th century BCE. Herodotus goes on to write of a seven-year drought around the year 630 BCE which forced the inhabitants of Thera to send colonists to
Cyrenaica in today's
Libya. This settlement was so successful that Thera long enjoyed a good reputation as the mother city of
Cyrene despite its own relative unimportance. A collection of 760 coins were found dating from the 6th century BCE, which give evidence of a modest amount of trade links to
Athens and
Corinth to the west and
Ionia and
Rhodes to the east. The role of the city changed in the second half of the 3rd century BCE when the
Ptolemaic wartime fleet for the entire
Aegean Sea was stationed in the city's harbor in
Hellenistic times. The city was completely rebuilt for the officers; the former layout was replaced by a regular street grid, and imposing buildings in the form of
peristyle houses were erected. The fleet was withdrawn around 145 BCE, and historic records from the city are completely lacking until about the year 1. In
Roman times starting in the middle of the 1st century BCE the island and city were part of the Roman
province of Asia, and although no high officials resided on the island Thera was relatively prosperous and significant, thanks to elaborate construction projects and the fact that Therans managed to attain high positions, including twice the office of provincial high priest. In the first third of the 3rd century the dissolution of the Roman Empire was also reflected by the absence of reports about the island. During
Byzantine times, Thera as a diocesan town was again more frequently mentioned; up into the 5th century it was the only urban settlement on the island of Santorini. As was the case with the entire region, it subsequently lost importance. In the year 726 it was covered by a layer of
pumice after a relatively small eruption of the volcano of Santorini and shortly thereafter the city was given up. Information about the destruction comes from the reports of
Theophanes, a Byzantine chronicler. As there are only slight traces of the earlier settlement, descriptions of the city primarily relate to its
Hellenistic golden age and later developments. == Ptolemaic garrison ==