Vingulmark (Old Norse Vingulmǫrk) is the old name for the area in Norway which today makes up the counties of Østfold, western parts of Akershus (excluding Romerike), and eastern parts of Buskerud (Hurum and Røyken municipalities), and includes the site of Norway's capital, Oslo. During the Middle Ages, Vingulmark was an administrative unit limited to Oslo, Bærum and Asker.
Olaf Tryggvason (960s – 9 September 1000) was King of Norway from 995 to 1000. He was the son of Tryggvi Olafsson, king of Viken (Vingulmark, and Rånrike), and, according to later sagas, the great-grandson of Harald Fairhair, first King of Norway. He is numbered as Olaf I.
Olaf was important in the conversion of the Norse to Christianity, but he did so forcibly within his own kingdom. He is said to have built the first Christian church in Norway in 995, and to have founded the city of Trondheim in 997. A statue dedicated to him is located in the city's central plaza.
Tryggve Olafsson (Old Norse: Tryggvi Óláfsson; Norwegian: Tryggve Olavsson; born c. 928 in Ringerike – died c. 963 in Sotnes, Bohuslän, Västra Götaland, Sweden) was the king of Viken, Norway (Vingulmark and Rånrike).