On 22 June, the four Soviet fronts began counter-reconnaissance and probing actions all along Heeresgruppe Mitte’s front, stripping away its outpost line. Then at 0500 hours on 23 June, the Red Army unleashed a two-hour artillery preparation unlike anything the Germans had previously experienced. Most Soviet artillery units fired two basic loads of ammunition during the preparation, meaning that a battery of 122mm howitzers fired 640 rounds each.{45} Although well dug in, the front-line German infantry positions were badly battered. Around 0700 hours, the ground attack began with specially-organized assault groups moving forward to clear obstacles and eliminate forward German positions. Unlike previous offensives, the Red Army avoided sending large masses of infantry forward until forward obstacles were breached and ensured that these assault groups were provided with adequate engineer support. The new PT-34 mine-roller tank was employed for the first time in quantity and it proved a success at rapidly clearing lanes through minefields. Although the German forward defences in the AOK 4 and AOK 9 sectors was still strong enough to repulse the initial attacks, it was a different story in Reinhardt’s PzAOK 3 sector. The 6th Guards Army and 43rd Army from Bagramyan’s 1st Baltic Front punched their way through the German IX Armeekorps defence west of Vitebsk while the 5th and 39th Armies from Chernyakhovsky’s 3rd Byelorussian Front smashed the VI Armeekorps south of Vitebsk. By the end of the first day of Bagration, it was clear that the two Soviet fronts were attempting a double envelopment of the LIII Armeekorps in the Vitebsk salient.
Busch was at Hitler’s headquarters when Bagration began and did not immediately grasp the scale of what he was up against. Hitler ordered ‘no retreat’ and Busch obeyed, without protest. In reality, it was really up to the local German commanders to decide how to respond to the Soviet offensive and thus the normal quick-thinking style of decision-making that characterized earlier German operations was not really evident in this situation. On 24 June, the Soviets increased the scale of artillery preparation in all sectors and this time, achieved small breakthroughs against AOK 4 and AOK 9, as well. The problem was that the German units were trying to hold too much frontline with too few troops, so inevitably the Soviet assault groups would find a weak spot. Near Orsha, the AOK 4 split the 20 Tigers of s.Pz.Abt.501 up across a wide area, trying to contain multiple enemy assault groups, but the dispersion into platoon-size packets robbed the Tigers of their ability to influence the battle. Although the Tigers, assault guns and Pak guns managed to knock out a significant amount of Soviet tanks, it was soon apparent that the Soviets were advancing much more quickly than thought possible. Reinhardt’s sector was the hardest hit and his front collapsed first. For the Germans soldiers in the front line of Heeresgruppe Mitte, Operation Bagration struck like a tidal wave, inundating all their fixed defences at a terrifying rate.
Hans Jordan waited until 25 January before committing Kessel’s 20.Panzer-Division and then sent it to deal with the enemy breakthrough south of Bobruisk, in the XXXXI Panzerkorps sector. Kessel’s division did not move into combat as an integral whole, but in pieces, and it was surprised to bump into armour from the 1 GTC well behind the XXXXI Panzerkorps’ HKL. Near the village of Slobodka, Panzer-Abteilung 21 claimed to have knocked out 60 tanks from Panov’s 1 GTC, but lost about 30 Pz IVs. While Kessel’s Panzers were tied up with Panov, the Soviet 3rd Army punched through the XXXV Armeekorps east of Bobruisk and sent the 9 TC to envelop the city. After just three days of battle, Jordan’s AOK 9 was in serious trouble. In the middle of the German front, AOK 4 initially held together because it had some of the best units and Zakharin’s 2nd Byelorussian Front did not have its own armoured exploitation force. Yet when both flanks began to give way on 25 June, AOK 4 began falling back toward the Dnepr River and Orsha was overrun on 26 June. Chernyakhovskiy sent Burdeiny’s 2 TC down the Smolensk-Minsk highway in pursuit.
For Heeresgruppe Mitte, the real disaster occurred in the area in between VI Armeekorps and XXVII Armeekorps, where the 5th Army achieved a complete breakthrough when two German infantry divisions disintegrated. Choosing the right moment, Chernyakhovsky committed Rotmistrov’s 5 GTA into the breach and this time, the Soviet armoured wedge advanced rapidly into the depth of the German defences, overrunning artillery and support units. The collapse of the VI Armeekorps left Reinhardt’s right flank in ruins and Soviet infantry and armour moved in to encircle the LIII Armeekorps in Vitebsk. Reinhardt pleaded with Busch and Hitler to allow these units to retreat before they were surrounded, but this was refused. Instead, the Soviets surrounded LIII Armeekorps by 26 June and the formation attempted a breakout on 27 June that resulted in the loss of 30,000 German troops. Reinhardt’s broken PzAOK 3 retreated westward toward Polotsk. Rotmistrov’s armour poured into the German centre, wreaking havoc. The Panzer-Grenadier-Division Feldherrnhalle tried to act as a blocking force north of Orsha but it was easily batted out of the way, then encircled and destroyed.
By 27 June, it was obvious even to Hitler that Bagration was no normal Soviet offensive, since Heeresgruppe Mitte was giving way everywhere. Ignoring Busch’s belated requests to retreat to save his armies from imminent encirclement, Hitler began to act irrationally. He ordered the 12.Panzer-Division (equipped with nine Pz III and 35 Pz IVs) transferred from Heeresgruppe Nord to reinforce Jordan’s AOK 9, then relieved Jordan of command for his belated commitment of 20.Panzer-Division.{46} Yet before the lead elements of 12.Panzer-Division could begin arriving by rail, Rokossovsky began to complete his double envelopment of Bobruisk. In short order, the 20.Panzer-Division and the bulk of the XXXV Armeekorps and XXXXI Panzerkorps were surrounded. Kessel spearheaded a breakout effort on 28 June that managed to save part of his division and 12,000 German troops, but the rest were abandoned to their fate. When the 65th Army stormed Bobruisk on 29 June, two German corps and 70,000 troops had been killed or captured. Rokossovsky exploited his victory by dispatching a mixed armour-cavalry group east toward the rail junction Baranovichi, which would complicate the German ability to move in reinforcements against his flank.
With PzAOK 3 and AOK 9 virtually destroyed, von Tippelskirch’s AOK 4 was unable to hold on the Dnepr and fell back rapidly to the Berezina River, abandoning Mogilev on 28 June. Only six out of 20 Tigers from s.Pz.Abt.501 made it across the Berezina; the rest either ran out of fuel or were damaged. The German infantry divisions were in even worse shape since they had very few motor vehicles and their artillery was towed by horses – so they could not outrun Soviet mechanized units. Rotmistrov’s armour was hot on AOK 4’s heels, stomping on retreating German columns and his vanguard was approaching the Berezina. The 78.Sturm-Division, one of the best infantry divisions in the Heer, was surrounded and destroyed near Orsha. As the Germans retreated, they were also pounded by VVS airstrikes, which killed two German corps commanders on 28 June (Pfeiffer of VI Armeekorps and Martinek of XXXXI Panzerkorps). The AOK 9 headquarters was also bombed, knocking out critical communications links. On the same day, Hitler sacked Busch and replaced him with Model, although this officer also retained command over Heeresgruppe Nordukraine.