Cog replica Image unrelated to the article.

Archaeologists have discovered two shipwrecks from the mid-14th century during excavations in Varberg (Sweden):
the wrecks are merchant vessels known as cogs, a single-masted transport ship that first appeared during the 12th century on the Frisian coast. During the 13th century, cogs progressively replaced Viking-type ships in northern waters: they could carry more cargo than the knarr of a similar size and were more stable due to their flat bottoms. The lumber used for the first cog was felled after 1346 in the region that today consists of the Netherlands, Belgian, and north-eastern France, while the lumber from the second ship was felled between 1355 and 1357 in northern Poland. Read more on