4th Infantry Regiment, later the 4th Infantry Regiment of the Lithuanian King Mindaugas () was a Lithuanian Army infantry regiment that existed from 1918 to 1940 and was located in PanevÃÂà ¾ys.
The regiment was founded on 29 December 1918, when the Defence Ministry of the Lithuanian Republic allowed the officer Jonas Variakojis to assemble and command the PanevÃÂà ¾ys Region Defence Unit (). On 5 January 1919, Variakojis managed to salvage 70 rifles out of the retreating German Army and by 7 January, his unit received its first order. From 22 March, the unit is known as the Separate PanevÃÂà ¾ys Battalion () and from 20 June 1919 as the PanevÃÂà ¾ys Battalion ().
The military formation was fighting the invading Bolsheviks from its foundation, specifically near PanevÃÂà ¾ys, KÃÂdainiai and UkmergÃÂ. On 18-23 May 1919, the regiment took part in the Kurkliai-PanevÃÂà ¾ys operation, although it did not succeed in defending PanevÃÂà ¾ys. Much more successful was the soon after Kupià ¡kis-Utena operation from 26 May to 3 June, during which Kupià ¡kis, Rokià ¡kis and Alà «kà ¡ta were liberated. The regiment pushed the Bolsheviks beyond the Daugava river.
From 15 October 1919, the regiment fought the Bermontians.
For its victorious battles, the à  iauliai town gave the unit a flag on 1 November 1919, the same day the unit was called the 4th Infantry Regiment of the Lithuanian King Mindaugas.
On 26 July 1920, the regiment entered Vilnius and defended it against Polish attacks in the start of October, later engaging them in the Musninkai-Ã Â irvintos sector, later partaking in the Battle of GiedraiÃÂiai. During the Lithuanian Wars of Independence, 3 officers and 72 soldiers of the regiment were killed in action, while 121 soldiers were wounded in combat. Order of the Cross of Vytis was accorded to 33 officers and 198 soldiers of the regiment.
In 1922, the regiment was moved to PanevÃÂà ¾ys. In 1926, it was given the flag of the 3rd Class Order of the Cross of Vytis with the inscription: "God, help us defend the Fatherland's liberty and honour". The regiment was part of the 1st Lithuanian Infantry Division, whose subunits were sometimes located in Kupià ¡kis ir UkmergÃÂ.
With the Soviet Occupation of Lithuania, the regiment was renamed as the "4th Infantry Regiment" on 25 July 1940 and disbanded on 30 August 1940. On the disbanded regiment's basis, the Red Army's 215th Rifle Regiment was formed on 9 September 1940.