He was commissioned shortly before the outbreak of World War I, and served with Austro-Hungarian forces on the Eastern and Italian Fronts as a junior officer in the Imperial-Royal Mountain Troops.

Immediately after the war, Mikl served in the Volkswehr militia which was formed to resist the incorporation of his home town of Radkersburg into the newly created Kingdom of Serbs, Croats and Slovenes.

Later in 1943, he was appointed to train and command the 392nd (Croatian) Infantry Division, and led it in fighting against the Yugoslav Partisans before dying of wounds inflicted in the last month of the war.

As part of the 22nd Rifle Division of the III Corps, Mikl's unit arrived at the area of Zolochiv, Galicia to take up a position on the Zolota Lypa River.

[7] On 2 June 1915, LIR 4 received orders to join the fighting in the Kolomyia region, where the Russian army launched an offensive and the Austrians suffered serious reverses.

For his actions and "demonstrated personal bravery", Mikl was awarded the Military Merit Cross 3rd Class with War Decoration (German: Militärverdienstkreuz III.

[8] By late September 1915, LIR 4 had been transferred to the Bovec valley in the Julian Alps on the Southern Front, and Mikl had been promoted to Oberleutnant (first lieutenant) and placed in command of the 2nd Company.

In August 1915, Italian Alpini troops had captured an advanced position about 1 kilometre (0.62 mi) southwest of the 2,208 m (7,244 ft) Rombongipfels peak, on a rocky outcrop called Cuklahöhe.

At the end of June, the parent regiment was transferred back to Galicia to reinforce the Austro-Hungarian forces being hard-pressed by the Russian Brusilov Offensive, and then returned to the Southern Front where it remained until the late autumn 1917, fighting in the 8th, 9th, 10th and 11th Battles of the Isonzo.

[18] In 1919, Mikl served as adjutant in the 1st Battalion of the Volkswehr militia,[20][14] which used arms provided by the provincial government of Carinthia to make an unsuccessful attempt to recapture Radkersburg from forces of the Kingdom of Serbs, Croats and Slovenes.

[26] Mickl remained in command of the 7th Rifle Regiment during occupation duties in southwestern France, redeployment to Germany, and during the division's preparation for the invasion of the Soviet Union.

On 6 September, his regiment joined the Siege of Tobruk taking up positions at Ras el Mdauuar until the end of October, when it became part of the composite Afrika (Special Purpose) Division and prepared for an attack on the fortress.

The division was the main reserve formation of Army Group North,[36] and when Mickl joined his brigade headquarters it was located on the coast near Narva west of Leningrad.

On the frontlines, 200 kilometres (120 mi) east of Nevel, Soviet forces were threatening to break through around the Rzhev salient and encircle the German 9th Army, and on 21 November the 12th Panzer Division received orders to march for the front.

The fighting continued in snowstorms and extreme cold until 16 December, with Mickl forward directing the battle, which ended with the destruction of eight Soviet tank and rifle brigades in the Bely area.

After a few days rest, on 23 December Mickl's regiment marched to the north-east of Bely to stop Soviet forces moving into the Luchesa river valley.

On 30 January, Mickl arrived in Gera on leave to visit his wife Helene, and spent the next three months in the Army Headquarters officers' reserve pool (German: Oberkommando des Heeres Führerreserve).

In early May, Mickl was summoned to Berlin and assigned to the command of the 11th Panzer Division during the absence of Generalleutnant Dietrich von Choltitz, who had been suffering with heart problems.

[44] When Mickl took command, the 11th Panzer Division had not yet finished rebuilding after suffering serious losses during the December 1942 Operation Winter Storm, the attempted relief of German forces encircled at Stalingrad and during the Third Battle of Kharkov in February and March 1943.

By the evening of 6 July, XLVIII Panzer Corps had breached the first belt of the formidable Soviet defences,[50] and Mickl's division had reached the Pena river north and northeast of Cherkasskoye.

By 10 July they had reached a position east of the Kursk-Kharkov road, on the heights 2 kilometres (1.2 mi) south of Oboyan,[50] having defeated advanced elements of the Soviet 10th Tank Corps.

[49] At this point the previously rough terrain opened up, and with the aid of binoculars the men of the division could see the vast plain behind Oboyan in which the two pincers of Operation Citadel were planned to meet.

[51] On 17 July, these orders were cancelled, and over the next week, Mickl's division fought defensive battles against the Red Army, and conflict arose with his subordinate commanders and his key staff, who did not support his style of leadership, which was modelled on that of his mentor Rommel.

Four days later, Mickl returned to Gera, disappointed and resentful about the demotion, as he felt that he had made a good enough impression during the fighting to be retained as commander of the division.

The 847th Infantry Regiment then spread out along the coastline between Karlobag and Crikvenica, and supported by elements of the divisional artillery and pioneers they began building fortifications against a feared Allied invasion.

[62][63] In late February or early March the 847th Infantry Regiment, supported by an Ustaše battalion, advanced on Plaški (south of Ogulin) when they were stopped by deep snow.

In the same month, the 846th Regiment conducted an operation in the Gacka river valley around Otočac, and assisted the Croatian Home Guard in enforcing conscription orders on their own population in the divisional area.

Through the spring of 1944, the 846th Regiment used Jadgkommandos, lightly armed and mobile "hunter teams" of company or battalion strength, to conduct follow-up of sightings of Partisans, and transport moving through the Kapela Pass had to travel in convoy for security.

The division was able to restore a land connection with the NDH garrison of Gospić which had been reliant on supply from the sea since the Italian surrender, and drove three Partisan battalions out of the outskirts of Otočac.

[23] He identified that the Partisan 13th Division was using the Drežnica valley as a huge armoury, hiding captured Italian arms and ammunition in villages, basements, and even in fake graves in cemeteries.