P.S. I kept seeing bits and pieces I remembered, but it wasn't until we got to the big battle at the end that I was sure I had seen this before. The movie portrays it as the Swedish version of Agincourt (ah-jin-koor), i.e. Swedish archers devastated the invading Danish army.
The series also covers the battle at The Horns of Hattin in 1187 where Saladin crushed the Crusaders.