Prusa or Prousa (Ancient Greek: Προῦσα), or Prusa near Olympus or Prusa under Olympus (Προῦσα ἐπὶ τῷ Ὀλύμπῳ, Προῦσα πρὸς τῷ Ὀλύμπῳ), was a town of ancient Bithynia or of Mysia, situated at the northern foot of Mysian Olympus.
It is acknowledged by Dion Chrysostomus, who was a native of the town in the first and second centuries, that it was neither very ancient nor very large.
[1] It was, however, as Strabo remarks well governed, continued to flourish under the Roman emperors,[2][3] and was celebrated for its warm baths that bore the name of the "royal waters.
"[4][5] Under the Byzantine emperors it suffered much during the wars against the Ottoman Turks;[6] when at last it fell into their hands, it was for a time the capital of their empire under the name of Bursa, which it still bears.
Its site is occupied by the modern city of Bursa, Asiatic Turkey.