Battle of Visby

I came across this picture of a skull fused to a mail coif, from the 1361 Battle of Visby. The Swedish History Museum hosts the remains.

The issue at stake was, unsurprisingly, which government got to collect taxes. Gotland was paying taxes to the King of Sweden, but the Danes felt they had a claim -- and they also had professional fighting men with recent experience and what were at the time modern arms.

The Danish army was composed mainly of Danish and German troops, many mercenaries from the Baltic coast of Germany, with recent experience in the various feuds and wars between the German and Scandinavian states. These men would have worn what was known as Transitional armour, with iron or steel plates over vital areas and joints over a full suit of chain mail. They were led by Valdemar IV of Denmark. Against them was an army of Gutes, mainly freemen and minor nobles. The ordinary freemen appear to have worn more limited but still effective protection, with many skeletons that were excavated wearing a chain-mail shirt or a coat of plates to protect the torso. Some warriors may have worn a padded Gambeson or a leather jerkin or coat[.]

The battle is contemporaneous with the Hundred Years War, which is why this array of armor is said to be 'transitional.' The early battles of the Hundred Years War were fought mostly in mail armor; by the end of the war, articulated plate armor was common not just for nobles but for knights and men at arms. This occurred somewhere in the middle, and less centrally to Europe than were England and France at that time.