Riddarfjärden
Riddarfjärden (, "The Knight Firth") is the easternmost bay of Lake Mälaren in central Stockholm. Stockholm was founded in 1252 on an island in the stream where Lake Mälaren (from the west) drains into the Baltic Sea (to the east); today the island is called Stadsholmen and constitutes Stockholm's Old Town.
Prehistory and origin of Stockholm
The watercourse passing south of the old town of Stockholm first appears in historical records as the somewhat cryptic phrase: "What split off is called Stockholm" ("Stockholm heter det som sprack av"), found in a version of the "Saga of the Saint Olaf" by the Icelandic author Stymer Frode, preserved through a manuscript from the 14th century. Stymer explains, what today are the islands Södermalm and Stadsholmen was at the time united by an isthmus, and Saint Olaf of Norway (995-1030) produced the strait, in the saga called "Konungssund" ("King's strait"), by summoning assistance from superior forces. A slightly different version, undoubtedly the most famous, is the account of the Icelandic historian Snorri Sturluson (1178–1241). He retells, while King Olav of Norway raided the Lake Mälaren area, the Swedish king Olof Skötkonung (960s-1021/1022) hoped to trap him by pulling an iron chain over "Stocksund" ("Log Strait", e.g. modern Norrström passing north of the old town), a strait in addition guarded by a castellum and an army on either sides. The Norwegian king then dug himself through the southern isthmus and, helped by vivid streams produced by spring flood and favourable winds, managed to have his ships break through the foreshore and shoals, and finally escaped to the Baltic Sea. Snorri however adds, the Swedes refuted this version as drivel.