Second Swedish Crusade

The Second Swedish Crusade was a 13th century Swedish military expedition against the Tavastians, in present-day Finland, led by Birger jarl. A lot of the details of the Crusade are debated, but the end result was that eastern Finland came to be a part of the Swedish kingdom.

Background
Sweden had been starting to exert control over Finland at least since the beginning in the 13th century, starting with Finland proper. In 1220, Sweden tried to join in on the Baltic Crusades, but could not hold on to the foothold in Estonia. There are notes of Swedish churchmen, possibly led by Finland's bishop Thomas, being present in Tavastia ca 1230, and papal letters deplore how slowly Christianity gains ground in Finland. There were apparently a backlash against the missionaries, and in 1237, pope Gregory IX sent out a call for the Swedes to take up arms in a crusade against the "apostates and barbarians".

Interpretations
Unlike the doubted First Swedish crusade, there seem to be little doubt that Sweden's effort to christen Finland reached a culmination in the middle of the 13th century. Still, a lot of the details, including the year and the exact nature, has been the subject of debate.

Nature of the Crusade
Despite the Chronicles attempt to paint the Crusade as a war of conquest, it is likely it was more of an unusually bloody phase in an ongoing process by which Finland was incorporated in the Swedish state. Sweden had a central government, and a strong ideological force in the form of the Christian church. Finnish chieftains who joined up gained power and prestige.

Dating
The dating of the Crusade when the attack took place has been somewhat disputed. Attempts have been made to date the attack either to 1238-1239 or to 1256. Neither date has received wide acceptance. Dick Harrison finds the theory of an early crusade most probable, on the ground of the papal letter, which would also make the war into a properly sanctioned crusade, and the fact that Sweden was otherwise peaceful during that period.

"Taffwesta borg"
The Chronicle mentions an impressive castle that was built by the Swedes, "taffwesta borg". This has been interpreted both as Häme Castle (Swedish Tavastehus), as well as nearby Hakoinen Castle, but there is no archaeological evidence to support such an early dating.

Church reaction and reorganization
Probably related to preventing other parties from getting involved in the conflict, Pope Innocent IV took Finland under his special protection in August 1249, however without mentioning Sweden in any way. Finland's bishop Thomas, probably a Dominican monk, had resigned already in 1245 and died three years later in a Dominican convent in Gotland. The seat being vacant, the diocese had probably been under the direct command of the papal legate William of Modena whose last orders to Finnish priests were given in June, 1248.

Swedish Bero was eventually appointed as the new bishop in 1248/9, presumably soon after William's visit to Sweden for an important church meeting at Skänninge that ended on March 1, 1248. The so-called "Palmsköld booklet" from 1448 noted that it was Bero who gave Finns' tax to the Swedish king. Bero came directly from the Swedish court like his two successors. It seems that Swedish bishops also held all secular power in Finland until the 1280s when the position of the Duke of Finland was established.

In 1249, the situation was also seen clear enough to have the first Dominican convent established in Finland. There had been no monasteries in Finland before that. The convent was situated next to the bishop's fortification in Koroinen until the end of the century.

Swedish succession
As an unexpected side effect, Eric's Chronicle tells of how the expedition seems to have cost Birger the Swedish crown. As King Eric died in 1250 and Birger was absent from Sweden, the Swedish lords, led by Joar Blå, selected Birger's under-aged son Valdemar as the new king instead of the powerful Jarl himself.

Swedish rule in Finland
From 1249 onwards, sources generally regard Finland proper and Tavastia as a part of Sweden. The Diocese of Finland proper is listed among the Swedish dioceses for the first time in 1253. In the Novgorod First Chronicle Tavastians (yem) and Finns proper (sum) are mentioned on an expedition with Swedes (svei) in 1256. However, very little is known about the situation in Finland during the following decades. The reason for this is partly the fact that Western Finland was now ruled from Turku and most of the documentation remained there. As the Novgorod forces burned the city in 1318 during the Swedish-Novgorodian Wars, very little remained about what had happened in the previous century. The last Swedish Crusade to Finland took place in 1293 against Karelians.