Helgö was an important place for commerce from about 400 AD to approximately 750 AD. It probably had severeal different protectors. Without protectors it would have been difficult for Helgö to exist. One of these protectors was Hundhamra (what is now known as Norsborg). The finds from Helgö comes from many parts of the world. An example is a little Buddha statue from the 6th century, India. Probably these finds came from far away countries through the hands of merchants from northern Germany and France. They got furs and iron in exchange. During the late 8th century Birka was founded. Birka shows signs of a more thorough planning than Helgö. A special house was built for the warriors that were supposed to protect Birka and the tradesmen who lived there. A harbour was made with a line of poles put down under water level to protect the inlet from an enemy fleet. It was to Birka that Ansgar came twice during the 9th century in his tries to christen the inhabitants. About 970 AD were Birka abandoned. Exactly why is not clear.