In the middle of the 14th century the “Bergsmän", those who initiated iron production, received permission from the ruling King, Magnus Eriksson to extract iron. The area around Askersund became vital to Swedish iron production in the Middle Ages.
The King Gustav Vasa visited Askersund in 1550. The reason for this visit was that the Bergsmän delivered poor quality iron. Gustav Vasa thought that Askersund had a natural harbour and connections out to Lake Vättern and furthermore was situated between the poorly accessible and dangerous wilderness areas of Tiveden and Tylö Forests. The King decided that Askersund should become a market town. Two markets should take place per year, and these Spring and Autumn Markets still take place today.
Askersund received its city charter from Queen Christina´s Guardian government on 13 july, 1643. The Coat of Arms depicts a Blacksmith with a raised hammer.