The 'Dukhovshchina-Demidov Offensive Operation 2^nd Stage' was a Soviet part of the 'Smolensk Strategic Offensive Operation' and undertaken by the Kalinin Front (14 September/2 October 1943).

This was the third of the six sub-operations together constituting the 'Smolensk Strategic Offensive Operation': the other elements were the 'Spas-Demensk Offensive Operation' (7/20 August), the so-called 'Dukhovshchina-Demidov Offensive Operation 1^st Stage' (13/18 August), the 'Yelnya-Dorogobuzh Offensive Operation' (28 August/6 September), the 'Smolensk-Roslavl Offensive Operation' (15 September/2 October) and the 'Bryansk Offensive Operation' (17 August/3 October).

As ordered by the Soviet high command, the first stage of the 'Dukhovshchina-Demidov Offensive Operation' began on 13 August in an area some 35 miles (21.75 km) to the north-east of Smolensk. As in other parts of this sector of the Eastern Front, General Leytenant Aleksei I. Zygin’s 39^th Army and General Leytenant Konstantin D. Golubev’s 43^rd Army of General Andrei I. Eremenko’s Kalinin Front encountered serious opposition: in the course of the operation’s first day, for instance, the Germans delivered no fewer than 24 counterattacks by regimental-sized forces. The Soviet forces managed to advance only some 3.7 to 4.3 miles (6 to 7 km) during the next five days and, despite the fact that they inflicted heavy losses on the Germans, the Soviets also suffered heavy casualties and the offensive was suspended on 18 August.

Eremenko was promoted to the rank of army general on 27 August, and planned to resume the offensive against Generaloberst Georg-Hans Reinhardt’s 3^rd Panzerarmee, in particular General Hans Jordan VI Corps. Provided with air support by Generalfeldmarschall Robert Ritter von Greim’s Luftflotte VI, this was deployed in a well-prepared defensive position based on multiple lines behind layers of minefields, ditches and barbed wire entanglements further aided by its siting in terrain made more difficult by its forested and swampy terrain.

The concept of the revised operation called for the Kalinin Front to commit its left-wing forces in an attack toward Dukhovshchina in order to defeat the German force of as many as six division holding this sector and then. co-operating with the right-flank forces of General Vasili D. Sokolovsky’s West Front, to develop the offensive toward Rudnya and Vitebsk.

For the operation, Berzarin’s 39^th Army and part of Golubev’s 43^rd Army, totalling 12 divisions, were to be used once again. The V Guards Corps was in reserve, and air support was provided by General Leytenant Nikolai F. Papivin’s 3^rd Air Army. The main blow was to be delivered by the 39^th Army, and the Soviets created a force density in the planned 5.6-mile (9-km) breakthrough sector included 128 pieces of artillery and mortars, and 24 tanks per kilometre.

During the morning of 14 September, the 39^th Army and the left wing of the 43^rd Army went over to the offensive and, after breaking through the German first defensive zone in several sectors, and by the end of the day had advanced to a depth of between 1.85 and 8.1 miles (3 and 13 km) along a front of 18.6 miles (30 km). In four days of fighting, the German defence was broken, and during the night of 19 September the 39^th Army, with the support of bombers of the Long-Range Aviation arm, seized the major German defensive stronghold of Dukhovshchina on the axis toward Smolensk. In the Soviet liberation of this town, a major role was played by an artillery grouping created by the 39^th Army on the basis of the 103^rd High-Power Howitzer Artillery Brigade'

On 20 September, the 4^th Shock Army liberated Velizh and on the following day the 43^rd Army liberated Demidov. The German forces in the area of Dukhovshchina and Demidov had been defeated, and was now threatened by envelopment from the north. After the loss of Demidov and facing envelopment, the Germans had little option but to begin the withdrawal of their left-wing forces. Continuing their advance, the Soviet forces had by 24 September reached a line some 9.33 miles (15 km) to the south-west of Velizh, the Kasplya river and Demidov, a mere 6.2 miles (10 km) to the north of Smolensk. With the loss of their key positions, the Germans started on a major withdrawal to the west. On 29 September and building on its current success, the 39^th Army captured Rudnya, another German stronghold and communications centre on the axis toward Vitebsk.

By 2 October 2, the Kalinin Front’s lift-wing forces had reached s line from the area to the west of Ponizovye to Rudnya, where they ran into a well-organised German defensive arrangement and the offensive was halted.

The defeat of the German forces in the area of Dukhovshchina and Demidov was an important element in the successful completion of the 'Smolensk Strategic Offensive Operation', and the arrival of the Kalinin Front’s forces on the approaches to Vitebsk created conditions which favoured the subsequent offensive toward Vitebsk and the outflanking from the north of the German forces in Belorussia. Despite the limited availability of tanks and warplanes for direct support of the infantry, the Kalinin Front’s forces had managed to break through strong pre-prepared German defences in difficult forested and swampy terrain.