This is a long, relatively narrow, three masted sailing vessel with a long, overhanging bowsprit used in the Mediterranean for trade and also popular with the corsairs who plagued merchant shipping in the area. They were especially prized for their speed and manoeuvrability and were in use from the 16th to the 19th centuries. Quite a pretty ship it was, too. See what I mean.
While merchants relied only on sail to get where they were going the corsairs made several modifications. They added guns - close to thirty - and could carry 300-400 men with added oars so they could be brought along side other vessels to overrun them in calm waters. Nothing much has changed, has it. The only difference with modern day pirates, scattered as they are all over the world, is that they are likely to use motorised boats for a quick approach and get away.