Wiktor Thommée was born 30 December 1881 in Sventiany, Russian Empire (modern Švenčionys, Lithuania), to a Polish family of distant French provenance.

Twice wounded, he spent several months in various hospitals, after which he was dismissed from active service for recovery and joined the Trade Institute in Kharkov (modern Kharkiv, Ukraine).

After the outbreak of the Great War, Thommée joined the 276th Infantry Regiment and served with distinction as a commanding officer of a company and then battalion.

On 20 October 1922 he became the first officer of the Grodno-based 3rd Military Area Command (DOK III) and at the same time he started his studies at the Higher War School in Warsaw.

On 1 July 1923 he was promoted to the rank of brigadier general, and on 15 August 1924 he became the commanding officer of the 15th Infantry Division stationed in Bydgoszcz.

Renamed to Thommée Operational Group on 6 September, the unit was the only part of the Łódź Army not to suffer tremendous losses during the retreat from the borders.

Due to lack of supplies, food and water, Gen. Thommée negotiated the capitulation of his forces under the condition that all the soldiers were to be treated as prisoners of war and were to be set free.

Although initially the Germans honoured the treaty, on 7 November 1939, Thommée was arrested along with a large part of his staff and was sent to Germany.