Strängnäs has made its mark on Sweden's history: it was one of the strongholds of Lutheranism after Laurentius Andreae, the town's archdeacon, was converted to the Reformation cause. He proclaimed Gustav Vasa as the King of Sweden on 6 June 1523. Gyllenhjelmsgatan, a street lined with timber houses, was mapped out around 1640 to create access to the impressive cathedral. To the west, the maze of medieval streets has been preserved. Lillgatan is a street lined with red-painted houses dating from the 17C and 18C.