Finnish – Novgorodian wars The Finnish – Novgorodian wars were a series of conflicts between Finnic tribes in eastern Fennoscandia and the Republic of Novgorod from the 11th or 12th century to early 13th century . The wars ' effect on the Finns ' society contributed to the eventual Swedish conquest of Finland in around 1249 . The term used in Russian chronicles to refer to Novgorod ' s enemy , " Yem " , is highly obscure and probably referred to several different groups . Some of the groups identified as Yem may have been the inhabitants of Tavastland in south - central Finland , the West Finns in general , or a sub - group of Karelians on the northern coast of the Ladoga . Early developments . The only known written sources on the Yem - Novgorodian wars are contained in the medieval Russian chronicles . The Russians and " Yem " had frequent conflicts from the 11th or 12th century onwards . The eastern Finnic peoples Votes , " Korela " ( interpreted as Karelians in general or more specifically as the Karelians on the southwest coast of the Ladoga ) and Izhorians are all mentioned as allies to Novgorod , said to have been fighting against Yem even without Novgorod ' s direct involvement . The earliest possible mention of hostilities is from the Laurentian Codex which records in passing that the Novgorodian Prince Vladimir Yaroslavich was at war with the " Yam " in 1042 . The Yam are also mentioned as tributaries to Novgorod in the Primary Chronicle , but they disappear from sources later on . It is disputed whether " Yam " was an earlier form of " Yem " or an altogether different people , perhaps living east of Lake Onega . Conflicts certainly began in the early 12th century , however information on them remains very scarce . According to the Novgorod First Chronicle , another Prince of Novgorod , Vsevolod Mstislavich , and his troops from Novgorod were at war with Yem during a great famine in 1123 . The chronicle leaves any further developments of the conflict open , including the whereabouts of the fight . Yem pillaged Novgorodian area in 1142 , but were defeated near Ladoga with 400 casualties . Coincidently or not , Swedes attacked Novgorodians in the same year as well . Korela , now under Novgorodian influence , were at war with Yem in the following year , but were forced to flee , losing two ships . Yem attacked Russian soil again in 1149 with 1000 men . Novgorodians , totaling 500 , went in pursuit of the Yem , utterly defeating them with Votes , a Finnic tribe in alliance with Novgorod . Votes , today almost extinct , lived south of the present - day Saint Petersburg , probably making this the deepest attack that Yem ever made into Russian territory . After a long pause in open hostilities — at least in the chronicles — a Novgorodian called Vyshata Vasilyevich led his troops against Yem in 1186 , returning unharmed with prisoners . It is not clear whether he took his forces to fight in the land of Yem or to defend his country against an intrusion . Reasons for the renewed fighting have not been identified . Korela accompanied Novgorodians for yet another attack against Yem in 1191 . This time the fighting is clearly said to have taken place " the land of the Yem " , the first such entry in Russian chronicles . The assailants " burned the country and killed the cattle " . Very hypothetically this may have been the same attack that was mentioned in a much later Swedish chronicle " Chronicon episcoporum Finlandensium " by Bishop Paulus Juusten from the mid - 16th century that knows Russians to have burned " Turku " in 1198 , at the time of Bishop Folquinus . Russian chronicles have no information about a conflict that year . It should be noted that the town of Turku did not exist before the end of the 13th century . After this , there is no information on further Novgorodian conflicts for several decades . It is also impossible to confirm whether the 1191 war resulted in a brief Novgorodian rule in parts of Finland or Karelia . However , a later chronicle entry from the mid - 1220s said that Russian princes had not been able to dwell in the land of Yem . Swedish and Papal involvement ? At the same time , Sweden and Novgorod were in conflict as well . Pope Alexander III , in his letter to the Archbishop of Uppsala and Jarl Gottorm of Sweden in 1171 ( or 1172 ) , perhaps refers to the Finns ' struggle against Novgorod by demanding Sweden take over Finnish fortressess in exchange for protection . In the late 15th century , historian Ericus Olai claimed that Bishop Kol of Linköping ( d . 1196 ? ) had been the " Jarl of Finland " ( " Dux Finlandiae " ) , possibly leading Swedish troops temporarily situated in Finland . He may have been in a military role similar to that of Jon jarl who allegedly spent nine years overseas fighting against Novgorodians and Ingrians at the end of the 12th century . Also noteworthy is the so - called First Swedish Crusade which according to several 15th - century sources took place in 1150 . The crusade is only known from later legends that presented the expedition ( if it ever took place ) as a Christian mission , headed by a saint king to baptize heathens . However , it seems to have followed the exceptionally edgy 1140s with both the Yem and Swedes fighting against Novgorod . Some historians have seen it as a direct reaction to the failed Yem expedition in 1149 , associating it with the co - operation mentioned by the Pope 20 years later . In 1221 , Pope Honorius III was again worried about the situation after receiving alarming information from the Archbishop of Uppsala . He authorized the unnamed Bishop of Finland to establish a trade embargo against the " barbarians " that threatened the Christianity in Finland . The nationality of the " barbarians " , presumably a citation from Archbishop ' s earlier letter , remains unknown , and was not necessarily known even by the Pope . However , as the trade embargo was widened eight years later , it was specifically said to be against the Russians . Russian sources mention Swedish - Yem co - operation in 1240 at the earliest ; it was then that were mentioned as one of the Swedes ' allies in the little - documented Battle of the Neva . The first reliable mention of Yem being a part of Swedish forces is from 1256 , seven years after the conventional dating of the so - called Second Swedish Crusade . Final war . The final known conflict between Yem and Novgorod took place in the 1220s , following decades of peace , at least in the chronicles . After having secured his power in Novgorod by 1222 , Grand Prince Yaroslav II of Vladimir organized a series of attacks against Estonia , Yem and Karelia . The offensive against Yem took place in winter 1226 – 27 . The same winter Yaroslav , son of Vsevolod left Novgorod over the sea against Yem where no else Russian prince had been able to dwell ; and he conquered the land and returned to Novgorod praising God with many prisoners . When those who were accompanying him could not handle all the prisoners , they killed some of them but released many more . The Yem retaliatory expedition in summer 1228 against Ladoga , allegedly with more than 2000 men ended in disaster , as described by the Novgorod First Chronicle . The Yem came to Lake Ladoga to war , and word about that came to Novgorod on the Ascension Day of the Christ ( 6 . 8 ) . And Novgorodians took their barges and rowed to Ladoga with prince Jaroslav . Vladislav , the bailiff at Ladoga , and the people of Ladoga did not wait for the Novgorodians , but went after them ( Finns ) in boats where they were fighting , met with them and fought them ; and then came night , and they ( people of Ladoga ) landed on an island , but Finns were on the coast with prisoners ; for they had been fighting close to the lake near the landing place , and in Olonets . The same night they asked for peace , but the bailiff and the people of Ladoga did not grant it ; and they killed all the prisoners and ran into forests , after abandoning their ships . Many of them fell there , but their boats were burned . - - And of those who had come , 2000 or more were killed , God knows ; and the rest ( who had not fled ) were all killed . The war seems to have been the end of independent Yem - Novgorodian conflicts . Based on Papal letters from 1229 , the unknown Bishop of Finland took advantage of the chaotic situation by taking over non - Christian places of worship and moving the see to a " more suitable " location . On the bishop ' s request , the Pope also enforced a trade embargo against Novgorodians on the Baltic Sea , at least in Visby , Riga and Lübeck . A few years later , the Pope also requested the Livonian Brothers of the Sword send troops to protect Finland . Whether any knights ever arrived remains unknown . Novgorodian wars were a factor contributing to the eventual Swedish conquest of Finland around 1249 . Under Swedish rule , the wars continued to rage in Finland as a part of Swedish - Novgorodian Wars .