This was a Soviet component of the third and last stage of the 'Bagration' summer offensive of 1944 (5/27 July 1944).
As such, the 'Białystok Offensive Operation' was an element of the pursuit phase of 'Bagration', and was launched after much of Generalfeldmarschall Walter Model’s Heeresgruppe 'Mitte' had been encircled and destroyed.
After eliminating the German pocket to the east of Minsk, in which General Kurt von Tippelskirch’s (from 18 July General Friedrich Hossbach’s) 4th Army had been trapped, the bulk of General Polkovnik Georgi F. Zakharov’s 2nd Belorussian Front was ordered to capture Volkovysk and then advance toward Białystok. General Leytenant Ivan T. Grishin’s 49th Army, however, was further employed in reducing the Minsk pocket until mid-July. Air support for the operation was provided by General Polkovnik Konstantin A. Vershinin’s 4th Air Army.
After the fall of Minsk on 3 July in 'Bagration', the Oberkommando des Heeres could call on few reserves to help check the Soviet advance. On the Białystok axis, the remaining German forces were organised into a Sperrgruppe (blocking group) under the command of General Helmuth Weidling. This comprised Generalleutnant Karl Decker’s 5th Panzerdivision, Generalmajor Georg Haus’s 50th Division, Generalleutnant Hermann Flörke’s Kampfgruppe 'Flörke', SS-Gruppenführer und Generalleutnant der Waffen-SS Curt von Gottberg’s Kampfgruppe 'von Gottberg', and part of SS-Brigadeführer und Generalmajor der Waffen-SS Helmuth Becker’s 3rd SS Panzerdivision 'Totenkopf'. The blocking group thus included several new groupings as well as the very few troops who had escaped from the area east of Minsk.
To the south, the German defence was conducted by the northern wing of Generaloberst Walter Weiss’s 2nd Army, which had been reinforced, notably with Generalleutnant Gustav Heistermann von Ziehlberg’s 28th Jägerdivision, in the hope of effecting a breakthrough to the formations of Heeresgruppe 'Mitte' still trapped in the area to the east of Minsk. The German effort was aided by the presence of old fortifications and defence works from World War I and earlier.
Under the overall command of Model, the German forces involved in the forthcoming battle were the remnants of the 4th Army, namely the Sperrgruppe 'Weidling' that was later redesignated VI Corps) and the northern part of the 2nd Army, namely General Friedrich Herrlein’s LV Corps.
The Soviet forces committed to the offensive were Zakharov’s 2nd Belorussian Front (Grishin’s 49th Army and General Leytenant Ivan V. Boldin’s 50th Army, and Vershinin’s 4th Air Army).
By 11 July the 50th Army had forced crossings of the Niemen river to the south of Dokudovo and moved forward against Weidling’s forces, crossing the Kotra river by 13 July and reaching Grodno two days later. Its LXIX and LXXXI Corps stormed Grodno during the morning of the next day.
On the northern flank of Marshal Sovetskogo Soyuza Konstantin K. Rokossovsky’s neighbouring 1st Belorussian Front, General Leytenant Aleksandr V. Gorbatov’s 3rd Army took Volkovysk in fighting against the LV Corps.
On 23 July Hossbach, commanding the 4th Army and with the agreement of Model, committed Generalleutnant Hans Källner’s newly arrived 19th Panzerdivision to a counterattack with the intention of cutting off the Soviet spearheads in the Augustów forest. One regiment surprised the Soviet forces in Grodno (and claimed, probably optimistically, to have destroyed some 180 tanks) before turning to the south in the direction of Białystok. A second regiment recaptured Lipsk, but then was forced to withdraw to assist the first regiment’s disengagement. For lack of resources, though, the German counter-offensive failed, but revealed the exhaustion of both the Soviet and German troops in comparison to fresh units.
The 2nd Belorussian Front had successfully forced the entire length of the Niemen and Svisloch rivers by 24 July, and Boldin’s 50th Army, with support from the III Guards Cavalry Corps, took or retook the eastern part of the Augustów forest and part of the outlying fortifications of Grodno which the Germans had retained after their counter-offensive. There was intense fighting as the 50th Division attempted to defend the highway linking Grodno and Białystok. The 3rd Army had meanwhile reached the outskirts of Białystok and, despite strong resistance from the LV Corps, stormed and took the city by 27 July after several days of street fighting. The Soviets estimated that the German losses during the 'Białystok Offensive Operation' were in the order of 30,000 men killed and 1,011 taken prisoner, but did not reveal their own losses.
The 'Białystok Offensive Operation' had proved largely successful in terms of its immediate tactical objectives: by the end of July the Soviets had taken the important communications centres of Grodno and Białystok. The Soviet lines of communication had become dangerously extended and their troops were exhausted, however, and the Soviet advance slowed as Model gradually organised an effective defence through judicious management of the few units available to his Heeresgruppe 'Mitte'. The 2nd Belorussian Front’s final objective in 'Bagration' was to advance to the Narew river in the 'Osovets Offensive Operation'.