The Dromon was the principle warship of The Byzantium Navy. They can trace their design style in the region to around the 7th Century onward. The Dromon possibly started out as a Commerce and Merchant trade vessel (before being adapted for military). Dromon's were built along the same lines as a Galley (using both human and wind power for propulsion). Although some early Dromon's may still have retained the ancient Ramming Spur (located at the ship's front and often below the waterline), for a time. As the rise of ship borne cannon weapons quickly rose, it's need disappeared (9th or 10th Century). The sail arrangement for The Dromon was either squared or triangular. Their development encompassed 1 to 3 Main Masts. Crews could range from 30 to several hundred (depending on size). After the 12th Centuries, Domon-type vessels were regulated to transport duties in The Mediterranean and Indian Oceans (until their general replacement).