Kyrre, Oslo became a cultural centre for Eastern Norway. St. Hallvard became the city's patron saint and is depicted on the city's seal.
In 1174, Hoved�ya Abbey (Hoved�ya kloster) was built. The churches and abbeys became major owners of large tracts of land, which proved important for the city's economic development, especially before the Black Death.
During the Middle Ages, Oslo reached its heights in the reign of King Haakon V. He started the building of Akershus Castle and was also the first king to reside permanently in the city, which helped to make Oslo the capital of Norway.
In the end of the 12th century, Hanseatic traders from Rostock moved into the city and gained major influence in the city. The Black Death came to Norway in 1349 and, like other cities in Europe, the city suffered greatly. The churches' earnings from their land also dropped so much that the Hanseatic traders dominated the city's foreign trade in the 15th century.
1600s
Over the years, fire destroyed major parts of the city many times, as many of the city's buildings were built entirely of wood. After the last fire in 1624, which lasted for three days, King Christian IV decided that the old city should not be rebuilt again. His men built a network of roads in Akershagen near Akershus Castle. He demanded that all citizens should move their shops and workplaces to the newly built city of Christiania.
The transformation of the city went slowly for the first hundred years. Outside the city, near Vaterland and Gr�nland near Old Town, Oslo, a new, unmanaged part of the city grew up with citizens of low status.
1700s
In the 18th century, after the Great Northern War, the city's economy boomed with shipbuilding and trade. The strong economy transformed Christiania into a trading port.
1800s
In the 19th century, several state institutions were established and the city's role as a capital intensified
