October 1939

5th October 1939

The Soviet Union requests that Finland send a delegation to Moscow to discuss changes to the border between the Soviet Union and Finland.

9th October 1939

Finland's ambassador to Stockholm, Juho Kusti Paasikivi arrives in Moscow for talks with Molotov and Stalin. In response to the increasing tensions with the Soviet Union and the need to prepare for a potential conflict, the Finns, under the guise of additional refresher training, began to mobilize their reserve forces.

12th October 1939

The Soviet Union demands of the Finnish delegation in Moscow, that they agree move the border on the Karelia Isthmus back to within 30km of Viipuri, cede the islands of Suursaari, Tytarsaari in the Gulf of Finland, agree to lease them the Hango Peninsula for 30-years, with rights to build a naval base on it and cede the Kalastajansaarento Peninsula in the far north of Finland. In compensation the Soviet Union proposed to cede to Finland the small settlements of Repola and Porajarvi in eastern Karelia.

14th October 1939

With the Finns suspicious of the Soviet Union, having seen its recent occupation of the Baltic states they decided to reject the Soviet demand and work on a more acceptable counter offer.

23rd October 1939

Finland delivers its counter-offer agreeing to some smaller less strategically important areas in the Karelian Isthmus and offering to cede the area of Terijoki. Finland also suggested strengthening the existing non-aggression pact between the two countries to address Soviet security concerns and proposed a limited military cooperation to ensure mutual security without compromising its sovereignty.

31st October 1939

In a full meeting of the supreme soviet, Molotov publicly rejects Finland proposals and reaffirms the Soviet Union's full list of territorial demands issued on the 12th October.

November 1939

14th November 1939

With the Finns unwilling to concede to all of the Soviet Union's demands, Stalin, viewing the situation as urgent, authorises preparations for an invasion of Finland.

26th November 1939

The Red Army stages a false flag attack, shelling the town of Mainila on the Soviet side of the border and accusing Finland of being responsible for the incident.

29th November 1939

The Soviet Union breaks off diplomatic relations with Finland.

The Initial thrusts by the Soviets into Finland and the Finnish Counter moves which prevented the invasion from reaching its goals.

30th November 1939

Without a declaration of war, the Soviet Union launches an invasion of Finland. The Leningrad Military District, commanded by Lieutenant General Kiril Meretskov deploys five armies for the operation: - 7th and 13th Armies are to push up the Karelian Isthmus with the objective of capturing Viipuri.
- 8th Army is to attack north of Lake Ladoga towards Tolvajarvi and secure areas of western Karelia.
- 9th Army will advanced towards Kuhmo and Suomussalmi in central Finland, intending to cut Finland in half by reaching Oulu.
- 14th Army will targeted the Petsamo and Salla areas in Northern Finland. With around 465,000 Soviet troops, divided into 29 divisions and 8 armored brigades, equipped with approximately 2,500 tanks and over 1,000 aircraft, they face around 300,000 Finnish soldiers, organized into 8 divisions, with about 30 tanks and 114 aircraft. The Soviets were confident of an easy victory. Soviet bombers attack Helsinki, resulting in the deaths of 61 Finns. In response to the Soviet invasion, Finland officially declares a state of war and begins to fully mobilise its forces.

December 1939

1st December 1939

The Soviet Union officially establishes the Finnish Democratic Republic, a puppet government led by Finnish communist Otto Wille Kuusinen, in the town of Terijoki, which immediately accedes to the Soviet demands. The Soviet Union broadcasts propaganda messages claiming this government, which is intended as a Soviet-friendly alternative to the legitimate Finnish government, has the support of the Finnish people. This was an attempt to undermine the Finnish government and justify the invasion. In Central Finland, the Soviet 163rd Rifle Division and an independent tank brigade having crossed the border at Juntusranta, while the 44th Rifle Division crossed at Raate, force the defending Finnish forces of about battalion strength, to conduct a fighting retreat towards the village of Suomussalmi.

2nd December 1939

The League of Nations issues a strong condemnation of the Soviet Union's invasion of Finland and demands an immediate halt to hostilities.

3rd December 1939

Finnish forces complete their fighting withdrawal on the Karelian Isthmus from the border area into the prepared defences of the Mannerheim Line, a heavily fortified position stretching across the width of the Isthmus. With their forces now consolidated, the Finns expected this defensive line to provide a solid defensive position to prevent further Soviet advances whilst inflicting heavy casualties on any further Soviet attacks.

6th December 1939

The Red Army launches its first major offensive against the Mannerheim Line using overwhelming numbers of heavy artillery, tanks, and infantry. However, a determined Finnish defence repulses these attacks along the entire length of the line, inflicting significant casualties in the process. Despite the ongoing war, Finland celebrates the anniversary of its declaration of independence from Russia in 1917.

7th December 1939

Finnish units withdraw from Suomussalmi but destroy the village to deny it to the Soviets. The Soviet 163rd Rifle Division captures the village but is unable to advance any further. Denmark, Sweden, and Norway declare their neutrality in the ongoing conflict, reaffirming their commitment to stay out of international wars and maintain peaceful relations. Britain and France decide to provide military support to the Finns, including arms and equipment. They also plan to send troops to assist in their defence. However, the firm neutrality of Sweden and Norway prevent any substantial support from reaching Finland.

8th December 1939

The Finnish 27th Infantry Regiment conducts a counter-attack against the Soviet 163rd Rifle Division at Suomussalmi, in an attempt to recapture the village.

9th December 1939

In an effort to revitalize military operations against Finland, Stalin orders Marshal Kliment Voroshilov to take over command of the Leningrad Military District from Meretskov, who is reassigned to lead the 7th Army instead. The Finns halt their counterattack against the Soviet 163rd Rifle Division at Suomussalmi, unable to recapture the village with their limited forces. The Finns now move over to guerrilla tactics in order to harass and weaken the Soviet forces while they rebuild up their strength in the area.

14th December 1939

With the authority of the League of Nations now severely diminished, it resolves to expel the Soviet Union for its invasion of Finland and encourages member nations to give all possible support to Finland. The USA, which isn't a member of the League, makes strong protests to Moscow, condemning its invasion of Finland.

17th December 1939

The Soviet 7th and 13th Armies begin a major offensive against the Mannerheim Line in the Summa area with around 120,000 infantry, two tank brigades, and support from over 200 aircraft. The aim is to break through and capture Summa along with the key road junction of Lahde, thereby opening up the way for an advance on Viipuri. Following an intense barrage, Red Army engineers are able to create several holes in the Finnish 5th Division's defensive line. However, poor coordination of Soviet forces and strong resistance from the Finns, who were well-prepared in their defences, hamper progress and causing heavy Soviet casualties preventing a breakthrough.

19th December 1939

With Finnish anti-tank and wire entanglements still largely intact, further heavy Red Army attacks are beaten off by the Finns around Summa, again inflicting heavy losses on the Soviet infantry. Some isolated groups of Soviet tanks are able to break through to the Finnish rear, but without infantry support, they are eliminated piecemeal.

22nd December 1939

With the Red Army unable to decisively breach the Mannerheim Line at Summa and having suffered around 7,000 casualties and the loss of at least 50 tanks, the offensive is called off.

23rd December 1939

The Finns launch a counter-attack on a 25-mile front from Lake Koulemajarvi to Lake Muolaanjarvi, using the 1st and 6th Divisions of the II Corps. Designed to take advantage of the failure of the Soviet offensive at Summa, the planning was poor and hurried, leading to only limited reconnaissance of Soviet defensive positions. Beginning at 6:30 a.m., the Finnish units immediately started to suffer heavy losses. By the end of the day, having sustained more than 1,300 casualties with limited gains to show for it, the offensive is cancelled.

27th December 1939

Reinforced with two additional infantry regiments (11th and 65th), the Finns launch a major assault against the Soviet 163rd Rifle Division, driving it out of Suomussalmi and inflicting heavy casualties. They captured a sizable number of prisoners, with the remainder of the division retreating in disorder across the frozen lakes.

January 1940

1st January 1940

Following the defeat of the 163rd Rifle Division at Suomussalmi, the Finns move quickly to attack the Soviet 44th Rifle Division, which is halted and strung out along the Raate Road. The Finns cut the road at many points, chopping up and isolating much of the division and blocking its retreat.

7th January 1940

Colonel General Semyon Timoshenko's Northwest Front takes over command of the Soviet 7th and 13th Armies on the Karelian Isthmus from the Leningrad Front, with ommand of all forces to the North of Lake Ladoga being assigned to the Karelian Front under command of Lieutenant General Mikhail Kovalyov.
Timoshenko is given explicit orders to plan and launch a new offensive within 25 days to breakthrough the defences of the Mannerheim line and is given permission to request whatever forces he needs for the offensive. He immediately transfers in 12 Rife divisions and 6 regiments of artillery and orders a thorough reorganisation and retraining programme of the formations on both Fronts. The Soviet air force is also ordered to begin an intensive bombing campaign against Finnish rear areas, particularly administrative targets, rail infrastructure, armament factories and ports in an effort to disrupt the supply situation at the front for the Finnish formations who were to bear the brunt of the coming offensive. Finnish forces complete the destruction of the Soviet 44th Rifle Division along the Raate Road, as its remaining elements are forced to surrender, having been surrounded without supplies since the 1st January. In what became known as the Raate Road Massacre, many Red Army soldiers froze to death near the road, lacking adequate winter equipment and being unable to move off-road due to the Finnish ski troops controlling the surrounding countryside.

8th January 1940

With the Soviet defeat at Suomussalmi and the destruction of the better part of two Red Army divisions, this marked the end of Soviet attempts to cut Finland in two. The Finns had demonstrated their effectiveness in using guerrilla tactics, mobility, and their ability to exploit harsh winter conditions to outmanoeuvre and defeat the numerically superior Red Army, inflicting around 29,100 casualties.

Finnish troops inspect abandoned Soviet T-26 and BT-5 tanks on the Raate Road on 8 January 1940.

29th January 1940

The Soviet Union attempts to reopen negotiation with the Finns using Sweden as an intermediary and indicating that they might withdraw their support from Otto Kuusinen's puppet government in Moscow.

February 1940

Major Soviet offensive begins with the aim of breaking through the Mannerheim Line.

4th February 1940

Three Soviet bombers attack Helsinki, targeting the Kruunuvuori railroad bridge, which connects Korkeasaari and Kruunuvuorenranta. The bridge receives a direct hit from a 50-kilo bomb, destroying its supporting beams. The bombers dropped a total of 14 high-explosive and a similar number of incendiary bombs during the raid, which also damaged the nearby barracks and aircraft hangars. As a result of the raid, 14 people lost their lives and 179 were injured.

5th February 1940

Anglo-French plans to send an expeditionary force to Finland are confirmed with serious consideration given to disregarding Norwegian neutrality and landing the force in northern Norway which was eventually agreed.

12th February 1940

Sweden continues to refuse direct military aid to Finland, but allows volunteers to travel across the border to join the Finnish army. It also supplies humanitarian assistance, including medical supplies and food.

20th February 1940

Keen to negotiate an end to hostilities after making significant progress on the Karelian Isthmus following its recent breakthrough of the Mannerheim Line, the Soviet Union extends a new offer for peace talks to Finland.

23rd February 1940

The Soviet Union announces its final conditions for peace with Finland. These included ceding a significant amount of territory in Karelia, including the city of Viipuri. Additionally, areas around Salla were also demanded, along with a thirty-year lease for a naval base on the Hanko Peninsula and various islands in the Gulf of Finland. Sweden announces that it will not permit British or French troops to cross its territory to reach Finland.

March 1940

1st March 1940

The Soviet Unions peace ultimatum of the 23rd February expires without acceptance by the Finns.

5th March 1940

Facing up to a now desperate situation on the battlefield, a Finnish delegation led by Prime Minister Risto Ryti leaves Helsinki, bound for Moscow to negotiate peace terms with the Soviet Union.

6th March 1940

The Finnish delegation arrives in Moscow by train that evening.

7th March 1940

The Red Army's 7th Army makes progress in outflanking Viipuri with the 10th and 28th Rifle Corps advancing from the west, while the 19th Rifle Corps moves in from the east. The city is nearly surrounded. Meanwhile, in Moscow, preliminary discussions begin between the Finnish delegation and Soviet officials.

9th March 1940

Intensified peace negotiations continue in Moscow, with both sides discussing terms and conditions.

10th March 1940

With the seizure of a 5km wide bridgehead at Vilajoki, units of the 34th and 50th Rifle Corps of the Red Army's 7th Army, commanded by Lieutenant General Kirill Meretskov, advance into Viipuri following the Finnish military's decision to withdraw to avoid being surrounded. With the capture of Viipuri, Prime Minister Risto Ryti requests an immediate armistice from the Soviets, but this is refused.

Following its evacuation by Finland, Red Army soldiers advance into Viipuri on the 10th March 1940.

11th March 1940

With heavy fighting continuing as the Red Army attempts to advance beyond Viipuri, intense final negotiations take place in Moscow as the Finns desperately try to secure more favorable peace terms. British Prime Minister Neville Chamberlain announces plans for aid to be sent to Finland.

12th March 1940

The Finnish delegation in Moscow accepts Molotov's conditions to end the war. The Moscow Peace Treaty is signed that evening and is set to come into force at midday (Moscow Time) the following day. The terms of the Moscow Peace Treaty were harsh for the Finns and included: - Ceding western Karelia, including the city of Viipuri (Finland's second city), along with parts of the Salla area and the Rybachiy Peninsula in Northern Finland.
- The islands of Seiskari, Lavansaari, Tytarsaari, and Suursaari in the Gulf of Finland were also to be ceded.
- Granting the Soviet Union a 30-year lease on the Hanko Peninsula for a naval base. In return, the Soviet Union agreed to: - Withdraw its troops from the areas it had occupied during the war that were not to be ceded.
- Drop their recognition of the Kuusinen puppet government.

13th March 1940

The ceasefire between Finnish and Soviet forces comes into force at 11am Finnish time (12 noon Moscow time), thus ending the Winter War.

29th March 1940

Soviet Foreign Minister Vyacheslav Molotov reports to the Supreme Soviet that the Red Army has suffered an estimated 126,875 killed, died of wounds, or missing, along with 206,534 wounded during the conflict. The Finns later report their losses amounted to 26,662 killed and another 44,557 wounded.