Prehistory and origin of Stockholm
According to the Chronicle of Eric, written in the 1320s, Stockholm was founded by Birger Jarl around 1250 as a lock to the Lake Mälaren region ("laas fore then sio", "lock before that lake") in order to prevent pirates from reaching the seven cities and nineteen parishes around it. Another medieval source ("Visbyannalerna"), however, claims the city was founded in 1187 following a pagan pillaged the city of Sigtuna, and as there was an "Earl" named Birger around at that time too, the disputed origin of the city are likely to remain obscure and some historians choose a diplomatic interpretation saying there was some sort of fortification around by the mouth of lake Mälaren when the city was founded during the second half of the 13th century. As Snorri mentions no city in his account but some sort of fortification called a "kastali" (in various manuscripts curiously said to be located east and west of "Stocksund"), it has generally been assumed this fortification eventually developed into the castle Tre Kronor located where still is the Stockholm Palace.
Culture in Stockholm
The city's oldest section is Gamla stan (Old Town), located on the original small islands of the city's earliest settlements and still featuring the medieval street layout. Some notable buildings of Gamla Stan are the large German Church ("Tyska kyrkan") and several mansions and palaces: the "Riddarhuset" (the House of Nobles), the Bonde Palace, the Tessin Palace and the Oxenstierna Palace. The oldest building in Stockholm is the Riddarholmskyrkan from the late 13th century. After a fire in 1697 when the original medieval castle was destroyed, Stockholm Palace was erected in a baroque style. Storkyrkan Cathedral, the episcopal seat of the Bishop of Stockholm, stands next to the castle. It was founded in the 13th century but is clad in a baroque exterior dating to the 18th century.