In the modern era, the head of government has the title prime minister (Norwegian: Statsminister).
Whenever the King was present in Christiania, however, he assumed the highest authority, thus putting the governor or viceroy temporarily out of charge.
Although the office of Norwegian prime minister in Stockholm still existed, the real power and influence over state affairs was moved to the prime minister in Christiania, while prime minister in Stockholm became the second highest cabinet position, responsible for conveying the government's views to the King.
When the union was dissolved in 1905, the position of prime minister in Stockholm was abolished.
Since then the office of the Prime Minister of Norway has been in Oslo, except for the years of Nazi-German occupation during World War II when the Norwegian government was in exile in London.