The regiment was formed in July 1941 by Croatian volunteers from the Independent State of Croatia (NDH), including a Bosnian Muslim battalion.

On 31 January 1943, the 800 remaining Croatian legionaries, led by the unit's commander Marko Mesić, surrendered to the Soviet Red Army.

[3] By 25 June 1941, Poglavnik Ante Pavelić, the leader of the NDH, sent an envoy to Berlin to offer volunteers to serve on the Eastern Front.

[5] All volunteers of the 369th wore Wehrmacht service uniforms with a Croatian checkerboard patch incorporating the word Hrvatska (Croatia) on the upper right sleeve and the right side of their helmets.

[5] On 30 September 1941, Colonel Ivan Markulj sent 43 officers and NCOs and 144 soldiers back to the NDH due to illness and/or for disciplinary reasons.

In mid-January 1942, the 100th Jäger Division was deployed to the Stalino area to assist in fighting off a Soviet cavalry corps that had broken through the front line.

Radio Zagreb broadcast communications from the regiment's soldiers but censored material detailing death or capture by the enemy.

[10] Generalleutnant Werner Sanne, the 100th Jäger Division's commander, commended the regiment's successes over the winter, especially the actions of Lieutenant Colonel Marko Mesić's artillery battalion on 21–22 February 1942.

From mid-May 1942, the regiment was reunited under Colonel Markulj, after which the 100th Jäger Division joined in the final phases of the pincer attack on the Red Army bridgehead at Kharkiv.

[11] After the Second Battle of Kharkov, Colonel Markulj, Lieutenant Eduard Bakarec and six other regiment officers were awarded the Iron Cross First Class.

After participating in mopping-up operations in along the Don, the division rested briefly in September, and the regiment was re-organized after receiving reinforcements.

[8] Lt. Bakarec, who was the first Legion soldier ever to receive the Iron Cross 2nd class, was later wounded at Stalingrad and evacuated to Croatia, where he was killed on 5 July 1944.

The 100th Jäger Division, including the 369th Croatian Reinforced Infantry Regiment, was involved in the heavy fighting for the "Red October" factory and for Mamayev Hill during the Battle of Stalingrad.

[8] Sergeant Dragutin Podobnik was awarded Iron Cross Second and First Class and many Croat decorations, including one personally from Pavelic in September 1942 for his actions at Stalingrad.

Podobnik and his 18 men surprised the Soviets, captured the building without loss, and then handed it over to units from the German 54th Army Group.

[8] By January 14th, the regiment's section of the front line had reduced to 200 men held by some 90 remaining troops, all suffering from extreme cold, hunger, fatigue and lack of ammunition.

Erwin Juric claimed that Pavicic had received written orders signed by Sanne to leave Stalingrad by air on 15 January.

[13] Among the last Wehrmacht soldiers to leave Stalingrad by air were a group of 18 wounded and sick Croat legionnaires, including Lt. Barićević, who were flown out by Luftwaffe pilots and were landed on the last serviceable German airfield at Staljingradskaja near the 369th's artillery section positions on the night of January 22nd to the 23rd, 1943.The evacuation also saved the regiment's war diary and other documents.

On 2 February, the Legion became Soviet prisoners of war, including all officers, approximately 100, mostly wounded, sick, and frostbitten combat soldiers, and some 600 other legionaries from artillery and support units.

[8] The Legion prisoners assembled at Beketovka on the river Volga, where they were joined by some 80,000 mainly German as well as Italian, Romanian and Hungarian POWs.

[1] In the summer of 1943, one hundred legionaries and 6 officers, including Marko Mesić, were transferred to Suzdalj and later to Krasnogorsk near Moscow, where they met with most of the surviving Croat soldiers.