[2][3] Shortly after the outbreak of World War I on 28 July 1914, Larisch was mobilized on 2 August 1914 and received a hastened commission to Leutnant in September of that year.

[5] Larisch's mother-in-law, who had divorced Xylander in 1914 to marry the officer Eduard Ermekeil (31 October 1864 – 18 November 1941) in 1916, came from a family of Pomeranian landowners.

On 1 February 1932 he was transferred to the Command Office in Neustettin (also in Pomerania), where he witnessed Adolf Hitler's rise to power one year later: on 31 January 1933, he became Chancellor of Germany.

In the following years, disregarding the confining Versailles Treaty, the Nazi regime intensified the German re-armament (Aufrüstung) and the size of the military.

Shortly thereafter he was promoted to Major and in early October 1937 he was transferred to another Infantry School, this time to Hanover in Lower Saxony, as Taktiklehrer (Tactics Instructor).

Larisch spent a great part of the Phoney War there, from October 1939 to January 1940, again trusted with training duties, in light of his earlier experience.

It can be assumed that Larisch's superiors held his training skills in high regard, but still deemed him unfit for field service, as he was transferred away from the front and posted as a Tactics Instructor for Company commanders in the city of Königsbrück in Upper Lusatia on 10 January.

[2] The quality of the units' training in Königsbrück prompted the American military attaché to write to his superiors that he was "impressed" of the German tactics in the army manoeuvres there.

In July 1942, the more combat-effective parts of the 16th Infantry Division were transported to North Africa to fight with Erwin Rommel's Afrika Korps.

Larisch, still deemed unfit for active combat duty, remained in Greece, and from October to November 1942 he commanded one of the units of the Festungsdivision Kreta that were left behind, the 1st Fortress Brigade (Festungsbrigade 1) with HQ in Thessaloniki.

[13] In this capacity, Larisch was responsible for the protection of the essential railroad transport in the puppet Independent State of Croatia, from acts of sabotage by the partisan movement active there.

He returned to Croatia in August and, on 1 November 1943, he was given the command of the 78th Sturm Division, one of the strongest, best-equipped and most effective combat units of the Eastern Front.

When Larisch took over the command, the division was engaged in heavy fighting with the Red Army, as the Soviets attempted to capture the vital Moscow–Minsk highway, connecting Smolensk to Orsha.

When, in June 1944, the Soviets launched a massive offensive (Operation Bagration), the 129th Infantry Division initially escaped total decimation, like many of the units of Army Group Center, but suffered heavy losses during the fighting in Belorussia.

[16] Arguably, Larisch's finest moment came in late summer 1944, when his division was defending the Narew river against the Soviet assault.

The German units had set up strong defenses along the river, including trenches, barbed wire, obstacles and minefields, and manage to prevent the Soviets from breaking through.

[17] This defensive success was met with visible enthusiasm from Larisch's superiors: on 1 September 1944, he was decorated with the German Cross in Gold.

While the winter had caused the marshes to freeze, making the terrain impermeable to attacks, this line was smashed and the German units were forced to retreat.

"[19] After the war ended with the unconditional surrender of Germany on 8 May 1945, Larisch was able to evade capture for more than a month, but was arrested by American troops on 15 June 1945.

With the exception of his only son, who went missing in action on 1 July 1944 in the northern sector of the Eastern Front,[20] all of his immediate family had survived the war.