The invasion began at 0700 hours on November 30 with an opening bombardment by 600 guns on the isthmus frontier. The infantry and tanks began to advance at 0730. While the Finns were expecting an attack, its weight and scope "exceeded our worst apprehensions", according to the Finnish commander-in-chief, Marshal
C. G. E. Mannerheim. The Finns fell back, more quickly than planned due to Soviet tanks, until 7th Army halted just short of the Mannerheim Line on December 6. For the next 10 days the front went quiet, giving the Finns a respite to regroup. Meretskov took direct command of 7th Army from Yakovlev on December 9.
Battle of Summa 19th Corps faced the center of the Mannerheim Line in the Summa sector, defended by the Finnish
5th Infantry Division. The first large assault on the sector began at 1000 hours on December 17, following five hours of artillery fire and strikes by up to 200 aircraft. The attack was on two axes: on the left against Summa itself; and on the right along the Lähde Road, 2km to the northeast. Lähde itself, an important road junction, was several kilometres behind the line. Soviet sappers led the push, blowing up antitank boulders and wire entanglements, and were followed by 50 tanks in an unsupported wedge formation; coordination between the infantry and armor was almost non-existent. The 123rd was in the Corps' second echelon and penetrated the Line near Hill 65.5 ("Poppius"), but was cut off by bypassed Finnish units and forced to break out, at the cost of some 1,500 killed and wounded. A heavier strike against the Lähde positions began the next day, with 86 tanks backed by heavy artillery and air strikes. Finnish artillery knocked out 10 vehicles while still behind the line, and another 15 were disabled in close combat. The infantry failed to pass the line of boulders. On December 19 the "Poppius" bunker, a major fortified complex, was battered by close-range tank fire so that many of its steel embrasures were jammed. Overrun by infantry, it held out for 48 hours until a Finnish counterattack freed the ground around the position. 19th Corps was now low on ammunition and supplies, and had suffered enormous casualties. The fighting died out by December 22. The 123rd had lost most of its combat personnel.
Second phase At about this time Col. Philipp Fyodorovich Alyabushev was brought in from command of the
14th Rifle Division to take over from Colonel Stenshinskii. In addition, on January 7, 1940,
Komandarm 1st rank
S. K. Timoshenko took command of
Northwestern Front (former Leningrad Military District), with
Komkor G. K. Zhukov as his chief of staff. The
13th Army was created to take over the eastern end of the line. As part of their reform program the 123rd and the 35th Tank Brigade were pulled behind the front lines for replenishment and intensive training. Finnish fortifications, particularly the "Poppius" and the nearby "Million" complex, were reproduced on similar terrain. For the second phase of the offensive about 75 percent of Meretskov's 7th Army, altogether nine rifle divisions, five tank brigades, a machine gun division, and 50 guns per kilometre, would be concentrated on a 16km sector of the line from Summa to Lähde Road to Munasuo Swamp. The essential tactical approach was called "gnawing through". The Line would be pierced with an armored wedge, now with infantry support, and this would be systematically expanded with waves of fresh troops and tanks until the defense collapsed. The Finns were known to be stretched to the limit, and such a breakthrough in the Viipuri gateway sector would force the abandonment of the entire Mannerheim Line. The 123rd and 35th Tanks would form the tip of the wedge. Intensive reconnaissance, previously neglected, discovered the positions of about 75 percent of the front line fortifications. Some patrols even returned samples of the concrete for analysis. The assault detachments of the division carried out three full-scale rehearsals against the mock fortifications, including actual demolitions, as well as refining armor and artillery cooperation and support. The tanks were given limited but realistic objectives. Several other divisions were given similar intensive training. Timoshenko had thoroughly reorganized the artillery, now consisting of some 2,800 pieces of 76.2mm calibre up to 280mm. The latest radios would accompany the leading units to adjust fire, and a total of 108 guns would support the 123rd, most from Corps and Army sources. Many would be used in a direct fire role against "Million" and "Poppius"; a 152mm piece had been placed just 500m from the embrasures of the latter under cover of diversionary fire, while a 280mm gun was available against the former. Altogether, 300,000 shells would be fired in the first 24 hours, the heaviest bombardment since
Verdun. Timoshenko's plan was to greatly escalate the usual artillery and airstrikes against the Line on February 1, accompanied by strong local ground attacks, for 10 days, before going over to the general offensive on February 11. On February 10 the preparations widened across the entire front. A few hours before dawn the next day the 2nd Battalion of the 9th Regiment of the 5th Infantry Division relieved the battalion that had been defending the Lähde Road sector since January. Its 1st Company was assigned to "Million", the 2nd was in and around "Poppius", while the 3rd was on the left flank north of Munasuo. The battalion was significantly under strength, with some 400 effectives, and had little time to familiarize itself with the position. It was composed of Swedish-speaking Finns, which introduced a complication in communications. The two main strongpoints were backed by three more concrete bunkers, but they were 20 years old and had been damaged by shellfire. The morning temperature was -22°C with fog. The 123rd was tasked with eliminating both bunker complexes, and as Summa had proven so tough Lähde would be the sector of Meretskov's main thrust. Once the division pushed through the support line, those three bunkers about 1,000m to the rear, it would strike toward the road junction, which would force the Finns to retreat or suffer heavy casualties in counterattacks. The assault troops were issued a ration of vodka at dawn, and by 0800 hours both the 123rd and the 35th Tanks were in position. This was followed by a two-and-a-half hour artillery preparation, heavier than previously seen. The heavy guns sited for direct fire tore large chunks out of the concrete of "Poppius" and "Million" while also bending their armored shutters. At 1200 the entire 255th Rifle Regiment attacked the latter, while a battalion of the 245th, with two companies of tanks, went for the former. Stiff resistance at "Poppius" halted and broke the attack after 20 minutes. Alyabushev ordered another battalion forward, and the tanks showed fresh determination. Four were knocked out by shell fire but the remainder drove up to the bunker's firing ports, bringing their guns and machine guns to bear while shrugging off Finnish machine gun fire. While this had been tried before, the riflemen now protected the tanks against
Molotov cocktails and grenade bundles, and the few antitank guns had been disabled by artillery fire. The garrison had no option but to evacuate the strongpoint and take up the fight from what remained of the trenches around it. The 245th had lost about 200 killed within 100m of "Poppius", but at 1230 Alyabushev and his staff saw a red banner being raised over its roof. The Finnish 3rd Battalion at first faced only one battalion of the 245th Regiment, as the half-frozen Munasuo could not support the weight of tanks. With almost no cover along the fringes of the swamp the Soviet soldiers suffered so many casualties that survivors called the area "The Valley of Death". However, the Finnish commander, Lt. Hannu, was later forced to withdraw as a group of some 20
T-28 tanks began moving into his rear from the Lähde Road. The "Million" complex held all day against the 255th. Eventually surrounded, several times it was overrun by infantry, but each time it was cleared with grenades and sub-machine gun fire. Several men wedged their way inside, and fighting became hand-to-hand. The garrison platoon received several demands to surrender, but answered with obscenities. At 0500 hours on February 12 divisional sappers placed a 250kg block of explosive on top of a crack in the roof of the main chamber that had been caused by shellfire. The blast killed all the occupants of the chamber and left a hole some 10m wide. With just 50 men remaining the Finnish 1st Battalion continued to hold out, even getting one
Bofors antitank gun back in service and knocking out several tanks as they passed. Finally, at 1200 the survivors pulled back to the support line behind
Lake Summasjärvi. By dusk the 123rd and the 35th Tanks had taken a large oval of territory right up to this support line. No attempt was made to rush this position in the fading light; the division dug in. During February 11-12 all other attacks had either failed or been forced out of their penetrations by counterattacks. Mannerheim intended to strike the Lähde Road position with the bulk of 5th Infantry, but in the event two regiments were required to hold the line. The 14th Regiment was sent in on the morning of February 13, but two battalions were pinned down by intense artillery fire, air strikes, and tank probes. The remaining two succeeded in driving the 123rd off a hill north of Summasjärvi and getting two companies across the Munasuo, but artillery forward observers were able to stall the attack with heavy fire, and the survivors pulled back to the support line. At about 1500 hours the 35th Tanks launched a supported attack in full strength, leading to a close range melee near an antitank ditch. While tank fire blew apart a reinforcing log wall the riflemen filled the ditch with all means available. Following two-and-a-half hours of bitter fighting a wedge of 50 tanks broke through and advanced to the west, with the division continuing to provide cover from Finnish close-range weapons. The armor soon began overrunning the artillery lines. Just 1.5km before the Lähde Road junction the tanks halted for regrouping and reinforcements, despite having a clear run to Viipuri. This gave the Finns another respite and the opportunity passed. Planning for another counterattack against the penetration took place overnight on February 13/14, but was cancelled due to the lack of artillery support. The next day the Lähde salient was widened and parts of the support line were rolled up, at a cost to the division of the equivalent of a battalion. The Finns were now forced to evacuate the Summa sector, which had held out for 70 days. To defend against the next move from Lähde they had just the remnants of the 14th Regiment and some teenaged Civic Guards on the bare terrain of Kämärä Ridge, without time or means to dig foxholes. On February 13 the 123rd was recognized for its success with the award of the Order of Lenin, while on March 21 the 245th Rifle Regiment would receive the
Order of the Red Banner. Colonel Alyabushev was also awarded the Order of Lenin. At 1600 hours on February 15 Mannerheim authorized the general retirement to the Intermediate Line. While this Line was as strong as the Mannerheim Line in the Viipuri gateway sector, it was weak nearly everywhere else. 7th Army took Kämärä Station late in the afternoon of February 16 after a lengthy battle that cost both sides heavy casualties. The tanks reached the Intermediate Line by the afternoon of February 18 and charged ahead without infantry support, losing more than 50 over the next two days. By February 24 the line was beginning to break in several places. Timoshenko planned another general offensive for February 28, but Mannerheim had already ordered a withdrawal to the Rear Line, so this mostly met empty trenches. By March 4 the equivalent of 30 Red Army divisions, with 1,200 tanks and 2,000 aircraft, were hammering at the Rear Line. Fighting in the outskirts of Viipuri began the next day, and when the ceasefire began at 1200 hours on March 13 advance elements of 19th Corps were some 8km north of the city.
Between the wars On March 21 Colonel Alyabushev was promoted to the rank of
Kombrig, which was modernized to major general on June 4. He was placed at the disposal of the Main Personnel Directorate on December 19 and took command of the
87th Rifle Division on March 13, 1941. At the start of the German invasion it was in
5th Army near
Vladimir-Volynskii and was quickly torn apart in the frontier battles. Alyabushev was mortally wounded on June 25 leading a bayonet charge in an effort to break out of encirclement. Meanwhile, the 123rd was assigned to the new 23rd Army when it was formed on the Finnish border in May 1941. Col. Evgenii Efimovich Tsukanov had taken command when Alyabushev departed; he had previously led the 47th Rifle Regiment before serving for nearly three years as military attaché to Estonia. == Continuation War ==