Although Norway didn't reach its first million until 1822, the country really got its skates on in the 19th century and for a time had the fastest population growth in Europe.

By 1890, the population had already soared to two million, despite one million Norwegians emigrating to the United States between 1825 and the late 1920s.

“It wasn’t necessity so much as the hope of a better life in America than here at home that made people emigrate,” said Professor Stale Dyrvik at the University of Bergen.

“In the 1800s, Norwegian society saw an economic development that would have made it possible to keep the emigrants. Had they stayed in Norway, the population figure today would be somewhere between seven and eight million instead of five million,” he added.

Aside from mass emigration to the US, pest and plague have likely done most to stunt population growth over the centuries.

While the Black Death is widely accepted to have wiped out some two thirds of the population after 1349, there is less awareness of the devastating effects of the plagues that came before and after.

For instance, a plague that hit Europe in the 540s stuck around for some 150 years, decimating the population across the continent.

“Then it disappeared again from Europe for several hundred years. After the Black Death, there were several outbreaks of plague. Plague is probably what had the most lasting effect on developments in the Norwegian population until 1654, when we had the last major outbreak,” said Dyrvik.

For thousands of years, the population stayed low in Norway as hunting and gathering remained the main source of sustenance.

But with the rise of agriculture, the population grew at a rate that is difficult for researchers to chart.

“When calculating how many people lived in Norway before we got the census, there are two methods used. One is the tax rolls. We have tax lists from 1520.

“The second method, which must be used for the period before 1500, is to look at the number of farms and estimate how many people lived there. Using this method, a researcher of the medieval period has estimated that there were some 80,000 people in Norway around the year 800,” said Dyrvik.

The age of dizzying population growth began earnest when infant mortality rates dropped dramatically in the 1800s.

“From 1815, we had a birth surplus in Norway that meant the country had the fastest population growth in Europe,” said Dyrvik.

Improved diets and the introduction of a vaccination against smallpox also helped keep the figures more than healthy.

“I think, first and foremost, infant mortality is the one to watch. In the 1700s, around a third of all newborns died in the first month. From the late 1700s, this began to change. I think this is because mothers focused on long-term breastfeeding,” said Dyrvik.

In recent years, two thirds of Norway’s population growth has stemmed from an increase in immigration, while a third of the increase comes from more babies being born, Statistics Norway said.  

Norway’s population growth in figures.

– March 19th, 2012: Norway’s population set to exceed five million, according to Statistics Norway.

– 1975: February sees Norway's population reach four million.

– 1942: The population hits three million in the middle of World War II.

– 1890: A century of major growth swells the population to two million.

– 1822: Norway has one million inhabitants.

– 1769: Norway’s first ever census puts the population at 723,618.

– 1665: Norway home to 440,000 people, according to a Statistics Norway estimate.

– 1500: Black Death reduces population to 150,000-180,000.

– 1349: Between 300,000 to 550,000.

– 800 AD: An estimated 80,000 people live in Norway.

– 0 – 11,000 BC: Population in the tens of thousands following migration from the south.