After Sweden broke out of the Kalmar Union in 1521, Norway tried to follow suit,  but the subsequent rebellion was defeated, and Norway remained in a union with Denmark until 1814, a total of 434 years. During the national romanticism of the 19th century, this period was by some referred to as the "400-Year Night", since all of the kingdom's royal, intellectual, and administrative power was centred in Copenhagen in Denmark. In fact, it was a period of great prosperity and progress for Norway, especially in terms of shipping and foreign trade, and it also secured the country's revival from the demographic catastrophe it suffered in the Black Death. Based on the respective natural resources, Denmark–Norway was in fact a very good match since Denmark supported Norway's needs for grain and food supplies, and Norway supplied Denmark with timber, metal, and fish.