The origin of Bergenhus Fortress is debated among historians. Evidence suggests this location along the harbor was first occupied about 1070 by King Olaf Kyrre, the founder of Bjørgvin (now Bergen). When the city was Norway’s capital for nearly a century (1217 – 1314), this medieval fortress was the royal residence. Magnus VI, the king of Norway from 1263 to 1280, ordered the construction of this tower during his reign. It was expanded to five floors during the governorship of Erik Ottesen Rosenkrantz in the 1560s and given his name. Rosenkrantz Tower later served as a gunpowder magazine from the 1740s until 1930s. The tower is now a key feature of tours.