King Herod built the two jetties of the harbour between 22 and 15 BCE, and in 10/9 BCE he dedicated the city and harbour to Emperor Augustus.
The pace of construction was impressive considering the project’s size and complexity. At its height, Sebastos was one of the most impressive harbours of its time. It had been constructed on a coast that had no natural harbours and served as an important commercial harbour in antiquity, rivaling Cleopatra’s harbour at Alexandria. Josephus wrote: “Although the location was generally unfavorable, [Herod] contended with the difficulties so well that the solidity of the construction could not be overcome by the sea, and its beauty seemed finished off without impediment.”
When it was built in the 1st century BCE, the harbour of Sebastos ranked as the largest artificial harbour built in the open sea, enclosing around 100,000 m2
