structural:summarization, structural:expansion, information:highlighting
Early history

After the end of the Ice Age and the retreat of the ice sheet, the first settlers arrived in the Helsinki area around 5000 BC. Their presence has been documented by archaeologists in Vantaa, Pitäjänmäki and Kaarela. Permanent settlements did not appear until the beginning of the 1st millennium AD, during the Iron Age, when the area was inhabited by the Tavastians. They used the area for fishing and hunting, but due to the lack of archaeological finds it is difficult to say how extensive their settlements were. Pollen analysis has shown that there were agricultural settlements in the area in the 10th century, and surviving historical records from the 14th century describe Tavastian settlements in the area.

Christianity does not gain a significant foothold in Finland before the 11th century. After that, a number of crosses and other objects related to Christianity can be found in archaeological material. According to the traditional view, the Kingdom of Sweden made three crusades to Finland, thanks to which the region was incorporated into both Christianity and the Swedish Empire. Recent research has shown that these expeditions, to the extent that there were even three of them, were not the crusades that had been imagined. Later, the conquest of Finland was justified in terms of "civilisation" and "christianisation", and the myth of the Crusades was developed. It is more likely that it was a multidimensional combination of economic, cultural and political power ambitions.

The early settlements were raided by Vikings until 1008, and the Battle at Herdaler was a battle between the Norse Viking leader Olav Haraldsson (later King Olaf II of Norway, also known as Saint Olaf) and local Finns at Herdaler (now Ingå), not far from Helsinga, around 1007-8. The Saga of Olaf Haraldson tells how Olav raided the coasts of Finland and was almost killed in battle. He ran away in fear and after that the Vikings did not raid the coasts of Finland.

Later the area was settled by Christians from Sweden. They came mainly from the Swedish coastal regions of Norrland and Hälsingland, and their migration intensified around 1100. The Swedes permanently colonised the Helsinki region's coastline in the late 13th century, after the successful 'crusade' to Finland that led to the defeat of the Tavastians.

In the Middle Ages, the Helsinki area was a landscape of small villages. Some of the old villages from the 1240s in the area of present-day Helsinki, such as Koskela and Töölö, are now Helsinki districts, as are the rest of the 27 medieval villages. The area gradually became part of the Kingdom of Sweden and Christianity. Kuninkaantie, or the "King's Road", ran through the area and two interesting medieval buildings were built here: Vartiokylä hillfort in the 1380s and the Church of St. Lawrence in 1455. In the Middle Ages, several thousand people lived in Helsinki's keep.

There was a lot of trade across the Baltic Sea. The shipping route to the coast, and especially to Reval, meant that by the end of the Middle Ages the Helsinki region had become an important trading centre for wealthy peasants, priests and nobles in Finland, after Vyborg and Pohja. Furs, wood, tar, fish and animals were exported from Helsinki, and salt and grain were brought to the fortress. Helsinki was also the most important cattle-breeding area in Uusimaa. With the help of trade, Helsinki became one of the wealthiest cities in Finland and Uusimaa. Thanks to trade and travel, e.g. to Reval, people could speak several languages, at least helpfully. Depending on the situation, Finnish, Swedish, Latin or Low German could be heard in the Helsinki area.

Written chronicles from 1417 mention the village of Koskela near the rapids at the mouth of the River Vantaa, where Helsinki was to be founded.