Eskilstuna's history dates back to medieval times when English monk Saint Eskil made "Tuna" his base and diocese of the South coast of Lake M�laren. Saint Eskil was stoned to death by the pagan vikings of neighbouring town Str�ngn�s, 30 km east of Eskilstuna, trying to convert them to Christianity. Saint Eskil was buried in his monastery church in Tuna. Later the pagan city of Str�ngn�s was Christianised and was given the privilege of becoming diocese of South Lake M�laren. Later "Eskil" was added in to the word "Tuna". However, the town of Eskilstuna did not receive municipal privileges due to its proximity to the medieval city of Torsh�lla. The monastery of Saint Eskil was completely destroyed by Swedish king Gustav Vasa during the Protestant Reformation and was replaced with the royal castle of Eskilstuna House. The city's first city privileges were granted in 1659, and its boundaries included Tunafors and the newly founded town of Karl Gustavs Stad ("City of Karl Gustav"), located on the west side of the river. Karl Gustavs Stad was built around the iron forges of master smith Reinhold Rademacher, encouraged by King Karl X Gustav. The first products of the forges weres mall arms and artillery.
Karl Gustavs Stad was a free town from 1771, where manufacturers and craftsmen were allowed to establish tax-free workshops and factories. The town was merged with the rest of Eskilstuna in 1879.
The city grew enormously during the Industrial Revolution and became one of the most important industrial cities of Sweden, earning the nickname "St�lstaden" ("The City of Steel"). Aside from firearms, the city also produced cutlery, scissors, keys, machine tools and precision instruments. As a tribute to the steel industry, the figure of a steel worker is included in the city's coat of arms. Eskilstuna is sometimes called The Sheffield of Sweden, Sheffield being a (much larger) industrial city famous for the quality (and quantity) of the steel produced there. Both
