Battle of Summa

Infobox Military Conflict
conflict=Battle of Summa
partof=the Winter War


caption=
date=1st February – 15th February 1940
place=Summa Lahde Sector
result=Soviet victory — breaking of the Mannerheim Line
combatant1=flag|Finland
combatant2=flag|Soviet Union|1923
commander1=Harald ÖhquistCarl Gustaf Emil Mannerheim
commander2=Semyon Timoshenko
strength1=Third Division
strength2=?
casualties1=?
casualties2=

The Battle of Summa was fought between the Soviet Union and Finland. It was fought near the village of Summa (now Soldatskoye) along the main road leading from Leningrad to Viipuri.

As the Soviets found it too difficult to breach the line at the Summa sector, they attacked 10 km to the east in a sector known as Lähde. If they broke through here then they could encircle the Finns holding the Summa position. Timoschenko knew he could beat the Finns in a battle of attrition. His plan was to wear them down and go for an all out blow.

First large probing actions were launched against the Finnish lines. For 11 days the line held in all positions. Then the Soviets went all out on the 11th.

On the 12th of February a minor breach in the Finnish lines in the Lahde sector led to disaster. By that time so many breaches had occurred in the Mannerheim Line that the report wasn't treated with enough seriousness. The following morning a counter-attack was supposed to be launched by the entire 5th Division, the only reserve in easy reach of the frontline, but only one of the three regiments was available as the other two regiments had to be parcelled out elsewhere.

In the end only two Battalions launched a counter-attack against two entire regiments well supplied with armour and artillery. The attack was thrown back with heavy Finnish casualties. The Russians made efforts to exploit the sailent. One tank Regiment made it as far as the Lahde road junction but halted. With total victory in their grasp the Russians halted their armoured spearhead.

Many Finnish companies were reduced to half their original strength. One company had lost 86 out 110 men. Over-night from the 14th to the 15th the Finns began withdrawing the Summa position. On the morning of the 15th the Russians attacked an empty position at Summa with more than 100 tanks and two divisions. That afternoon Mannerheim ordered a general retreat to the Intermediate Line.