 A wide range of metalwork, including gold ornaments, are known from the following Migration Period (about 400–550 AD) and Vendel Period (about 550 –790 AD).Sweden's Iron Age is considered to extend up to the end of the Viking Age, with the introduction of stone architecture and the Christianization of Scandinavia about 1100 AD.The historical record up to then is sparse and unreliable; the first known Roman reports of Sweden are in Tacitus (98 AD).