War against Bermontians

In October 1919, the Kaunas Battalion, led by officer Edvardas Adamkavičius, fought against the Bermontians near Baisiogala, Raseiniai and Tauragė.

Polish-Lithuanian War

On 9 January 1920, a year after the formation's beginning, the battalion was transformed into a regiment, being given the name of the Samogitian Duke Butigeidis. The regiment was moved to Ukmergė to defend the Vepriai-Kurkliai line against the Polish Army. On 15 July, while the Polish were running from the Bolshevik onslaught, a part of the regiment, commanded by lieutenant J. Černius marched into Vilnius, and on August 26, the whole regiment garrisoned Vilnius. Later, the regiment was moved near Gardinas, but after Polish victories, the regiment was driven back to Vilnius. There was a brief respite because of the Suwałki Agreement.

Żeligowski's Mutiny

Żeligowski's soldiers pushed the 7th Regiment out of Vilnius, from where it retreated towards Ukmergė. In addition to other Lithuanian units, the regiment took part in the Battle of Giedraičiai, where the Polish Army was heavily defeated, stopping its offensive to Kaunas.

According to the plan of the commanding officer of the 7th regiment's battalion Teodoras Balnas, on the night of November 18–19, 200 selected soldiers surrounded the Polish 81st Grodno Rifles Regiment, attacking from the flanks and behind. The Polish unit was surrounded from 3 sides and was severely defeated. The Lithuanians took 200 prisoners of war, 2 artillery guns, 24 HMGs, around 200 wagons, 50 horses, 250 rifles, 9 mortars and 24 field kitchens.^[2]

After the end of the war, the regiment guarded the demarcation line in the surroundings of Ukmergė and Trakai.

Klaipėda revolt

In 1923, parts of the regiment were involved in the Klaipėda revolt, and hence were stationed in Klaipėda and Šilutė. In Klaipėda, the regiment was in formerly German barracks, while in Šilutė, they were in the Macikas Manor.