A Cog is a plank-built, square rigged sailing ship with one mast. Cogs are most associated with seagoing trade in medieval Europe, particularly in the Baltic Sea region.
The earliest development seems to have been Celtic, though the cog was first noted in the Dutch city of Muiden in the 10th century. The round ships with oars that were used for Mediterranean sailing were not useful in the rougher Atlantic waters. The maneuverable Viking Longships lacked cargo capacity and could not use their sails against the wind. Attaching a ...
