The story of the so-called Lappland War is much more complicated. After Finns and Germans agreed on the so-called 'autumn manoeuvres' (that the Germans would retreat and the Finns advance according to a pre-arranged plan to avoid bloodshed between the former co-belligerents) in mid-September (the Soviet-imposed deadline for the German withdrawal was on 15 Sept.), for a couple of weeks things went as planned. But the Soviets soon discovered that something was amiss, and the Finnish leadership began receiving ultimatums demanding real action, or else the Red Army would come and drive the Germans away themselves.
On 22 Sept Lt. Gen. Hjalmar Siilasvuo is designated as the commander of the troops in northern Finland. Because Siilasvuo commanded the III Corps that was subordinated to the Germans during the Continuation War, it comes as a surprise to some that he is now to conduct the war against the Germans. The reason is simple: Siilasvuo never came along very well with his German superiors because he always verified all his orders with Mannerheim, and simply dragged his feet and obstructed any action that was contrary to Mannerheim's wishes. Siilasvuo also knows the land and the enemy.
On 30 Sept the Soviets present yet again another ultimatum calling for action. Worried Mannerheim calls to Siilasvuo, who reassures the old Marshal that there will be good news tomorrow. Already on two previous days there has been some fighting as Finnish troops has surprised Germans by advancing further and faster than was agreed, and trying to capture some bridges intact. On 1 Oct Infantry Regiment 11, commanded by Lt. Col. Halsti, invades Tornio (on the northernmost point of the Bothnian Gulf) by sea. The intention is to capture the town by surprise.
At the same time the Finnish Army starts advancing towards north. After fierce fighting Tornio and nearby Kemi are captured by 8 Oct. But that is not the end of the war. Most of the Finnish Lappland is in German hands, and they're not going to give up. The Finnish advance is slow, and the Germans devastate the countryside as they retreat (as a result the Germans are still particularly unpopular in northern Finland). For example the city of Rovaniemi, the capital of Finnish Lappland, is one victim of this policy. Generaloberst Lothar Rendulic declares on 9 Oct, that because of the Finnish Army's "base and unhonourable acts" all buildings owned by the state in Rovaniemi will be burned down. As a result the centre of the city is totally destroyed.
Despite the fighting in Lappland, the Soviets insist that the demobilisation of the Finnish Army should proceed. The first men are released on 1 Oct, and more and more will be as the time goes on. By the end of the year almost all of the veterans are released, and young conscripts has to finish the war in Lappland - the rest of the war was nicknamed as 'the Children's Crusade'. This means that the Finns has to become unaggressive and be content with advancing only after the Germans had withdrawn. The war stagnates into an occasional recon patrol probing the enemy positions.
In February 1945 the Finnish Cabinet is surprised to find out that there's still no formal state of war between Finland and Germany. This little oversight is remedied on 1 March 1945, when the Cabinet declares that a state of war has existed since 15 Sept 1944, the day the Germans tried to capture the island of Suursaari. At this point there is only a battalion of GebirgsjE4ger in KilpisjE4rvi, the north-westernmost tip of Finland, protecting the southern flank of the German Gerbirgsarmee fighting the Russians in northern Norway.
In late April the Germans begin withdrawing once more, and on 25 April 1945 the last German soldiers leave Finnish territory. The WWII is finally over for Finland. The Finnish losses in the Lappland War are 774 killed, 262 missing and 2904 wounded, the German losses are estimated as being about equal.