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 Mälaren. Saint Eskil was stoned to death by the pagan vikings of neighbouring town Strängnäs, trying to convert them to Christianity. Saint Eskil was buried in his monastery church in Tuna. Later the pagan city of Strängnäs was Christianised and was given the privilege of becoming diocese of South Lake Mälaren.
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 Torshälla. The monastery of Saint Eskil was completely destroyed by Swedish king Gustav Vasa during the Protestant Reformation.
The present Kloster Kyrka, a monastery church, was built according to plans by architect Otar Hökerberg . It was opened May 29, 1929. Above the main entrance is a sculpture depicting Saint Eskil. The entrance door to the church is surrounded by paintings of the apostles Paul and Peter. The old altar is high and wide staircases of stone leading up from the nave. The altarpiece from the 1600s is the work of the Flemish master Martin de Vos and represents the shepherds' adoration.
References:The Chapel of St. Martin is the only completely preserved Romanesque building in Vyšehrad and one of the oldest in Prague. In was built around 1100 in the eastern part of the fortified outer ward. Between 1100 and 1300, the Rotrunda was surrounded by a cemetery. The building survived the Hussite Wars and was used as the municipal prison of the Town of the Vyšehrad Hill.
During the Thirty Years’ War, it was used as gunpowder storage, from 1700 to 1750, it was renovated and reconsecrated. In 1784, the chapel was closed passed to the military management which kept using it as a warehouseand a cannon-amunition manufacturing facility. In 1841, it was meant to be demolished to give way to the construction of a new road through Vyšehrad. Eventually, only the original western entrance was walled up and replaced with a new one in the sountren side. The dilapidating Rotunda subsequently served as a shelter for the poor.