'Hornung' was a German operation in the rear area of Generalfeldmarschall Ernst Busch’s 16^th Army against so-called partisans, Jews and other 'undesirables' in the region of the Pripyet marshes in the Belorussian region of the German-occupied western USSR (8/26 February 1943).

The partisan forces were provided with leadership and supplies flown in or paradropped by Soviet aircraft based in safe areas, and their bases in the marshes were adequately provided with basic amenities such as hospitals, administration buildings and armouries, enabling these partisans to hold out for long periods between sallies to harass the Germans, either by cutting their lines of communication or by attacking convoys or rear-area installations.

Undertaken by a combined force of Sicherheitsdienst personnel, police and SS troops of the Kampfgruppe 'von Gottberg' under the command of SS-Brigadeführer und Generalmajor der Waffen-SS Curt von Gottberg, the operation was directed against the area of Hancewicze, Morocz, Lenin and Łuniniec, a thinly populated area of about 1,545 sq miles (4,000 km²) to the south-west of Słuck on the southern border of the Belorussia region, and was the last element of a three-operation sequence which had started with 'Erntefest I' and 'Erntefest II' in January farther to the north-east, and resulted in the deaths of 5,519 partisans and members of the local population and the deportation of another 7,378 persons to concentration camps.

The objects of 'Hornung' by von Gottberg, who was the senior SS official in Belorussia, included the prevention of the movement from the northern Polesie region of partisans who had entered Belorussia and Ukraine from the east and to avoid attacks on the railway line linking Brześć and Homel along the Pripyet river. According to the intelligence assessments of the commander of the Sicherheitspolizei and Sicherheitsdienst in Minsk, there were some 10,000 people in the area, which was also the 'home' of 34,000 partisans who were, according to the German security apparatus, organised as a Soviet republic with command offices, centres for recruitment and military training, sports facilities, churches and schools.

'Hornung' began with the destruction of the Słuck ghetto on 8 February, when more than 3,000 persons were killed. During the following week the designated operational area was combed systematically by the Germans forces, which comprised 13 battalions and numerous smaller units in five Kampfgruppen, but there was little in the way of real combat.

On 14/15 February the tactics were changed, as had originally been planned, and the second and longer phase of the operation began under the supervision of SS-Sturmbannführer Franz Magill, the deputy commander of the SS-Sonderbataillon 'Dirlewanger', as SS-Sturmbannführer Oskar Dirlewanger, its commander, had been wounded. This stage of the undertaking was designed to turn the operational area into a deserted no man’s land. Up to this time the death toll, excluding the Jewish population of Słuck, was 2,483 people, and the SS-Sonderbataillon 'Dirlewanger' now took the lead in the second phase of the operation, and other units involved were Kampfgruppe 'Binz' of the 23^rd Polizieregiment, the Einsatzgruppe 'B' and the Russian collaborationist Bataillon 'Rodianov'.

Overall command was vested in SS-Gruppenführer Erich von dem Bach-Zelewski. There are conflicting accounts of the second stage of 'Hornung', but in overall terms the operation was characterised by the destruction of many large villages: 1,046 people died in Lenin, 780 in Pusiczi, 787 in Adamowo and 426 in Kopacewiczi. The final death toll was 12,718 persons including the 3,300 Jews of Słuck. Only 65 prisoners and no deported labourers at all were mentioned.