Not really a pirate ship, but a ship nonetheless.
From Wiki
A dromon (from Greek δρόμων, dromōn, "runner") was a type of galley and the most important warship of the Byzantine navy from the 5th to 12th centuries AD, when they were succeeded by Italian-style galleys. It was developed from the ancient liburnian, which was the mainstay of the Roman navy during the Empire.