10 May 1941 – 20 August 1944: 2nd Mountain Division (until March 1942 it was a brigade)

17 October 1941: Mihai Viteazul Order 3rd class

2 November 1942: Knight’s Cross

15 February 1943: Mihai Viteazul Order 2nd class

1 January 1943: promoted to maj. gen.

20 August – 1 December 1944: Mountain Corps

15 November 1944: Mihai Viteazul Order with swords 3rd class

Ioan Dumitrache was born on 25 August 1889 in Ciorasti, near Ramnicu Sarat, being the only child of a modest peasant family. His military career began in 1909, when he entered the Infantry Officer School. He graduated in 1911, with the rank of 2nd lieutenant and was assigned to the 38th Infantry Regiment Neagoe Basarab in Braila. During WWI he was a 1st lieutenant in the same unit and in 1917 he was promoted to captain. He was wounded twice during the fighting in 1916-17. After the war ended, in 1919, he was admitted to the Military Academy, which he finished in 1921, being assigned to the staff of the 1st Vanatori Division. He was already major since 1920. In 1924 he was moved to the 1st Mountain Division in Sinaia. In 1929 he was promoted lt. colonel and named CO of the 2nd Mountain Battalion in Caransebes. After only two years he was moved to Bucharest, in the Territorial Command. In 1935, being promoted to the rank of colonel, he received the command of the 4th Mountain Group in Bistrita. Between February 1938 – March 1939 he was also the prefect of the Nasaud County.

On 10 May 1941, before Romania joined the war, he became brigadier general and was named CO of the 2nd Mountain Brigade, subordinated to the Mountain Corps of the 3rd Army. He stayed at the command of this unit for over three years, during the time span of the campaigns against the Red Army. It started the offensive in Northern Bukovina on 3 July and carried out heavy fights for Hotin with the retreating forces of the Soviet 12th Army. On 19 July, the 2nd Mountain Brigade crossed the Dnestr River and advanced towards the Bug River fighting with the rearguards of the 18th Army. On 25 July, while his troops were engaged south of Kapusteany, the command point of general Dumitrache came under the bombardment of Soviet heavy artillery, but fortunately he wasn't hurt. Eleven days later, on 5 August, he was again in danger. The 3rd Army had to execute a double enveloping maneuver with the Cavalry and Mountain Corps in the in the Seminovka and Voznesensk. However the Romanian columns got mixed up during the operation. In all the confusion, the Soviets counterattacked towards Krivoe Ozero and general Dumitrache and his staff barely escaped capture. The offensive continued and on 10 August the mountain troops reached the Bug River. After a ten day pause the Mountain Corps advanced to the Dnper, where it took up defensive positions on 1 September. The 3rd Army secured the left flank of the German 30th Corps.

On 16 and 17 September, the 2nd Mountain Brigade crossed the river at Berislav and then was deployed in defense in the Ulianovka and Malaya Belozherka areas in the night of 21/22. The counteroffensive of the Soviet 9th and 18th Armies north of the Azov Sea started on 23 September. The situation of the Romanian 3rd Army became critical. The 2nd Mountain Brigade resisted initially to the enemy pressure. On 25 September, however, the front was broken in the sector of the 15th Battalion at Ulianovka. General Dumitrache counterattacked with the reserves and managed to save the threatened battalion and establish a new defense line north of Malaya Belozherka. On 27 September, again powerful Soviet forces broke the front of the brigade, surrounding the 10th Mountain Battalion. However it resisted in the encirclement for two days and then its remnants managed to make their way to the Romanian lines. The 2nd Mountain Brigade organized a new defensive position 800 m south of Malaya Belozherka. In other parts of the brigade's front the mountain battalions resisted the attacks and stood their ground, even though Soviet tanks managed to get behind the first line and disturb the supply of the troops with food and ammunition and the evacuation of the wounded. On 28 September, the positions south of Malaya Belozherka were again attacked, but the assault was repulsed, allowing the German reinforcements to arrive.

The critical situation from the first days of the Soviet offensive was surpassed due to the stubborn resistance of the 2nd Mountain Brigade. At the beginning of October, the 9th and 18th Armies were surrounded by German and Romanian troops. Until 5 November, general Dumitrache's troops cleared the Berdiansk – Molotchinaya sector. Following this last operation, because the 2nd Brigade was the Mountain Corps' unit that had been most affected by the fighting in the previous months, it was sent back to Romania for reorganization. It arrived in its garrisons on 7 December. Thus ended the first campaign of brig. gen. Ioan Dumitrache During the almost five months of combat, his unit suffered 1,926 casualties. He was awarded the Mihai Viteazul Order 3rd class for the reoccupation of Hotin, at the beginning of the campaign.

In July 1941, the 2nd Mountain Division (the brigade had become a division on 15 march) was again sent to the front, to the Caucasus. At the beginning of August it passed the Don River at Rostov and advanced southwards, subordinated to the 1st Panzer Army. The first serious fighting occurred during the forcing of the Baksan River on 22 August. It managed to establish a bridgehead near Kysburun and after three days it took Height 910 that controlled the Baksan Valley. In the following days, the positions on the hill were relentlessly assaulted, but the 2nd Mountain Division resisted. During the night of 1/2 September 1942, however, general Dumitrache had to pull back his men over the river at the order of the 1st Panzer Army, because the German command feared the potential threat to the rear of the Axis positions of the Soviet bridgehead in the Sayuko Heights area. The retreat was executed very quickly and without losses. The 2nd Mountain Division received the mission to eliminate the bridgehead, which it did on 18 October, taking 400 POWs. Until that date the mountain troops had taken 1,858 POWs in the 1942 campaign.

On 25 October brig., gen. Ioan Dumitrache started the offensive towards Nalchik, forcing the Baksan River once again. The front was broken between the 295th Rifle and 2nd Guards Rifle Divisions. Until 28 October, after fierce fights in the hills and forests near Nalchik, the Romanian 2nd Mountain Division took the objective. It lost 820 men and captured 3,079 prisoners. For this action, general Ioan Dumitrache was later promoted and received the Mihai Viteazul Order 2nd class and the Knight's Cross of the Iron Cross.

In November the tide turned and the Red Army started its offensive in the Caucasus. The13th Panzer Division was surrounded near Mairamadag. The mission to reestablish the link with it was assigned to general Dumitrache. The 4th Mountain Group retook the Ordzonikidze – Alagir highway and allowed the German tanks to pull out. After several months of intense fighting, the division had lost much of its combat potential.

At the beginning of January 1943 a ordered retreat of the Axis troops in the Caucasus commenced. The 2nd Mountain Division arrived in the Taman Peninsula on 28 January and was subordinated to the German 52nd Corps from the 17th Army. In February it was strengthened with a German detachment and took up defensive positions on the western bank of the Beysuk River. Under the pressure of the Soviet offensive, the Axis troops were forced to pull back on successive positions. General Dumitrache's division arrived at Saboisky on 17 February. Four days later it retook the Vasilchenko village and at the beginning of March it cleared Belykov and the Svistyelniov Lagoons of Soviet troops.

Following these fights, the 2nd Mountain Division had depleted its last resources. It was campaigning for 203 days and its general and soldiers had won the respect of both the Romanian and German commands. No less than 478 Iron Crosses 1st and 2nd classes were awarded to its men. On 20 March it was taken out of the first line and sent to Crimea for reorganization and deployed on the Alma Valley.

Maj. gen. Ioan Dumitrache (he had been promoted in January 1943) was busy during the following months with the rebuilding of his division. The process wasn't finished in November, when the 4th Ukrainian Front started the offensive in Northern Crimea. On 10 November, general Dumitrache took over the command of a Romanian detachment, made up of troops from the 1st and 2nd Mountain, 10th and 19th Infantry Divisions, that had to contain a Soviet bridgehead south of the Sivash Sea. It did so until 12 December 1943, when the German 336th Infantry Division took over the sector. After his return to the 2nd Mountain Division, general Dumitrache commanded a vanatori de munte detachment that, between 29 December 1943 and 4 January 1944, together with the detachment led by brig. en. Leonard Mociulschi, eliminated over 3,700 partisans in the Yaila Mountains.

During the next offensive of the 4th Ukrainian Front in Arpil 1944, when the Soviet troops broke into Crimea, general Dumitrache's Divisionwas divided in two: one part at Sevastopol, securing a sector of the defense of Sevastopol and repulsing no less than 24 enemy attacks between 15 and 30 April 1944. The other part formed the Alushta Detachment that was sacrificed by the German command in order to allow the retreat of the Axis troops from the Kerch Peninsula. During the last days of the battle for Sevastopol, the remains of the 2nd Mountain Division were evacuated. Two battalions stayed behind and were subordinated to the 1st Mountain Division. After his return to Romania, general Dumitrache began once again to rebuild his unit that will distinguish itself again in the autumn of 1944, but against other enemies and under a different commander.

On 20 August 1944 he was assigned to the command of the Mountain Corps that was deployed on the Romanian-Hungarian frontier in Southwestern Transylvania. Following the events in Bucharest on 23 August 1944, the following day, German troops occupied key positions in Brasov, taking control of the railway stations and of important intersections. General Dumitrache organized quickly his more numerous forces into mixed detachments that, on 25 August, cleared the city of German troops and captured 500 POWs and 6 guns. Until 30 August he defended the front between Intorsura Buzaului and Homorod with troops of the 1st Mountain Division and of the 13th Infantry-training Division. It repulsed local attacks of German and Hungarian troops and blocked the roads for Germans retreating northwards from Wallachia. Another 300 POWs were tajen and 36 aircraft. From that day until 2 September he attacked and reoccupied the Aita Seaca and Biborteni areas.

The corps of maj. gen. Dumitrache was strengthened at the beginning of September. It was made up of the 1st Mountain Division, 3rd and 6th Infantry Divisions. On 7 September the Soviet-Romanian offensive in Transylvania started. The Mountain Corps, which was subordinated to the Romanian 4th Army, reoccupied Sfantul Georghe the following day and Odorheiul Secuiesc on 13 September. On 28 September 1944 it attacked on the Mures River and entered Targu Mures. The next offensive commenced on 9 October. The Mountain Corps pursued the retreating troops of Army Group Wöhler westwards. On 14 October general Dumitrache entered in Gherla. It was the last notable action of the Mountain Corps, because two days after it was pulled out of the first line and sent to its garrison in Brasov.

On 15 November 1944 he received the Mihai Viteazul Order with swords 3rd class. Only three Romanian generals received the model 1941 3rd and 2nd classes and the model 1944 3rd class of the order, Dumitrache being one of them. Incidentally all were mountain troops commanders. He was replaced at the command of the Mountain Corps by lt. gen. Radu Gherghe and he was named deputy commander. He remained in this position until 20 March 1945. In 1947 he was promoted to the rank of lt. general and then retired. On 3 January 1949 he was arrested and investigated for presumed war crimes. Ioan Dumitrache was released on 6 October 1950, because he couldn't be accused of anything. He settled down in Brasov, where he lived under surveillance by the Securitate until 6 March 1977, passing away at almost 88 years of age.