Early Finnish wars
Scattered descriptions on wars against Finland or by Finns to neighboring countries prior to the Swedish conquest has survived in Icelandic sagas, German, Norwegian, Danish and Russian chronicles and Swedish legends. The most important sources are Novgorod First Chronicle, Primary Chronicle and Eric Chronicles. Most of the early Finnish wars remain unhistorical and cannot be verified from reliable sources.
Conflicts with Swedes
Ynglingasaga tells about the first known military expedition to Finland. Based on saga's internal chronologies, the war presumably took place at the end of the 4th century, 6 generations before the semi-historical Swedish king Ohthere (Vendelkråka): However, it is disputed whether the Old Norse concept Finland refers always to the present country of Finland; alternatively it could have meant the land of the Sámi.
It happened one summer that King Agne went with his army to Finland, and landed and marauded. The Finland people gathered a large army, and proceeded to the strife under a chief called Froste. There was a great battle, in which King Agne gained the victory, and Froste fell there with a great many of his people. King Agne proceeded with armed hand through Finland, subdued it, and made enormous treasure.
My grandfather Thorgny could well remember the Upsala king Eirik Eymundson, and used to say of him that when he was in his best years he went out every summer on expeditions to different countries, and conquered for himself Finland, Karelia, Courland, Estonia, and the eastern countries all around --
However, all other accounts of the king exclude Finland from his conquests.
Finland was probably the same as Terra Feminarum which was attacked by Sweden in the 1050s, as described in Gesta Hammaburgensis Ecclesiae Pontificum (Deeds of Bishops of the Hamburg Church) by Adam of Bremen in 1075 CE. According to the source, the attack ended in the Swedish defeat, and led to the death of the king's son who was in charge of the campaign. Information on the conflict is however convoluted.
Medieval Swedish legends
The best-known Swedish war against Finland presumably took place in the 1150s known as the legendary First Swedish Crusade. Whether it ever actually happened, is however not certain as the information is based on the late 13th century legends.
Sweden eventually took over Finland during the so-called Second Swedish Crusade around 1249. By the end of the century, records of independent Finnish military activities ceased to surface.
Conflicts with Norwegians
The Kvens (Qwenas) harry the Norwegians across the moor, sometimes the Norwegians them. And there are very many fresh water lakes beyond the moors; and the Kvens carry their ships overland into the moors, whence they harry the Norwegians, they have very small and very light ships.
Legendary Orkneyinga saga tells about Nor who travelled from Kvenland to Norway and took over the entire country. Based on saga's internal chronologies, the war would have taken place on the 6th or 7th century. Another version of the saga, Hversu Noregr byggdist, however omits the Kvenland part completely.
According to Icelandic chronicles, Kvens were raiding in northern Norway in 1271:
Then Karelians (Kereliar) and Kvens (Kvænir) pillaged widely in Hålogaland (Hálogalandi).
Conflicts with Danes
Vague chronicle entries briefly mention Danish expeditions to Finland in the 1190s and 1202. Nothing is known about their results except what can be read from a papal letter from 1209 to the Archbishop of Lund which lets the reader understand the church in Finland be at least partly established by Danish efforts.
Conflicts with Novgorod
Finnic groups and the Republic of Novgorod waged a series of wars during the 12th and early 13th centuries. They probably contributed to the Finns' eventual subjugation to the Catholic Church and the Kingdom of Sweden.
List of Early Finnish Wars
- Ynglingan saga tells of campaign by Swedish king Agne to Finland. Finnish army was lead a person whos name in saga is translated to Froste.
- 7th century. Finnish warriors served in the courts of Denmark and Uppland.
- 9th century. Story of Norna-Gest tells of raids done by Kvens to Sweden. Ohthere of Hålogaland tells of skirmishes between Finns and Norwegians.
- 1008: Battle at Herdaler. Olaf II of Norway is defeated by Finns somewhere in Uusimaa.
- 1023: The prince of Novgorod Vladimir Yaroslavich makes a campaign against Finns.
- 1142: Finns make a campaign against Novgorod and Ladoga and are defeated.
- 1143: Karelians attack against Tavastians via sea, but escape after losing two ships
- 1149: Finns make a campaign with few thousand men against Votes who are supported by Novgorod with 500 men.
- 1155: Eric IX and English clergyman Henry make possibly the first Swedish crusade to Finland against Finns proper.
- 1186: Prince of Novgorod makes a campaign against Finns.
- 1187: Destruction of Sigtuna. Karelians pillage the city on 12 July. The Bishop of Uppsala and the Yarl are killed.
- 1191: Novgorod and Karelians make a campaign against Tavastians. Danes make a raid to Finland.
- 1202: Danes make a campaign to Finland which is lead by the Arcbishop of Lund Anders Sunesen and his brother.
- 1227: Prince of Novgorod Yaroslav II makes a campaign against Finns.
- 1228: Finns make a campaign to ladoga with over 2000 men. Yaroslav II makes another campaign to Finland.
- 1240: Battle of the Neva. Swedes, Norwegians, Finns proper and Tavastians makes a campaign against Novgorod.
- 1249-1250: Second Swedish crusade to Finland against Tavastians.
- 1253: Karelians raid against Germans in the area of Narva.
- 1256: Alexander Nevskiy makes a campaign to Finland after unsuccessful campaign of Finns proper, Tavastians and Swedes to Narva.
- 1257: Karelians make a devastating campaign to Sweden which lead Valdemar to ask Pope Alexander IV to start crusade against them.
- 1271: Karelians and Kvens attack Hålogaland in Norway.
- 1278: Prince of Novgorod Dmitry Alexandrovich decide to punish Karelians by conquering them.
- 1283: Swedes and Finns make a campaign to Neva and Ladoga area.
- 1292: Novgorod makes a campaign to Finland. Swedes attack Karelia and Ingria.
- 1293: Third Swedish crusade to Finland against Karelians.
- Norna-Gests þáttr, chapter 7. See also the English translation.
- Saga of Olaf Haraldson. See chapter 81. THORGNY'S SPEECH.
- Ottar's description of Kvenland.
- http://omacl.org/Heimskringla/haraldson1.html Saga of Olaf Haraldson. See chapter 8: The Third Battle.
- Íslenzkir annáler sive Annales Islandici ab anno Christi 809 ad annum 1430, pp. 140–141. Translation provided here is by the author of the article.
- Excerpts from different Danish chronicles mentioning Finland. In Latin. Hosted by the National Archive of Finland. See  and Diplomatarium Fennicum from the menu.
- Letter "Ex Tuarum". In Latin.
- "OMACL: Heimskringla: The Ynglinga Saga". omacl.org. Retrieved 2016-08-06.
- Nielsen, K. H. "Euran miekka skandinaavisesta näkökulmasta.". Viikinkejä Eurassa? Pohjoismaisia näkökulmia Suomen esihistoriaan. 2001. ISBN 9789529135615.
- "Fornaldarsögur Norðurlanda". www.germanicmythology.com. Retrieved 2016-08-06.
- "Ohthere's First Voyage (paragraph 5)". web.uvic.ca. Retrieved 2016-08-06.
- Edited by Joonas Ahola & Frog with Clive Tolley (2014). Fibula, Fabula, Fact: The Viking Age in Finland. Studia Fennica. p. 422.
- London Offices of the Society, 1914. "The Chronicle of Novgorod" (PDF).
- Line, Philip (2007). Kingship and State Formation in Sweden, 1130-1290. BRILL. p. 333. ISBN 9004155783.
- Edited by Martti Linna (1989). Suomen varhaiskeskiajan lähteitä. Historian Aitta.