The coastline has changed considerably in the last millennium due to post-glacial rebound. Originally there was a sea bay coming in from the north all the way into Uppsala. Roslagen is the modern name for the area which roughly corresponds to what was called Roden in the Middle Ages.
Roslagen is the name of the coastal areas of Uppland province in Sweden, which also constitutes the northern part of the Stockholm archipelago.
Historically, it was the name for all the coastal areas of the Baltic Sea, including the eastern parts of lake Mälaren, belonging to Svealand. The name was first mentioned in the year 1493 as "Rodzlagen".[1] Before that the area was known as Roden. Roden had a skeppslag (roughly translated: ship district), the coastal equivalent to the inland Hundreds.
When the king would issue a call to leidang, the Viking Age equivalent of military conscript service, the skeppslag in Roden was responsible for raising ships for the leidang navy.
The name comes from the rodslag, which is an old coastal Uppland word for a rowing crew of warrior oarsmen.[2] Perhaps, etymologically, Roden, or Roslagen, is the source of the Finnish and Estonian names for Sweden: Ruotsi and Rootsi.[3][4]
The area also gives its name to the endangered domesticated Roslag sheep, which originated from the area centuries ago.
Communications
The region is served by the Roslagsbanan, a narrow-gauge railway network from Stockholm, going as far north as Kårsta. The motorway E18 goes through Roslagen between Kapellskär and Stockholm.
