Promoted to Staff Captain, he was then sent to Brest-Litovsk as commander of a sapper company, and participated in the construction of fortifications for the Brest Fortress.

At the start of World War I, Karbyshev was involved in combat operations in the Carpathians under General Aleksei Brusilov’s 8th Army on the Southwestern Front.

With the February Revolution and the collapse of the Russian Empire, Karbyshev joined the local Red Guard in December 1917 while stationed at Mogilev-Podolsky (today Ukraine).

During the Russian Civil War, Karbyshev oversaw the construction of numerous fortifications, particularly the Kakhovka Platzdarm, and held senior positions at the headquarters of the North Caucasus Military District.

Karbyshev supervised engineering support for the assaults on Chongar fortifications and Perekop against the White movement in the Crimea.

His articles and manuals on the theory of engineering and battlefield operations and tactics were mandatory for reading by Red Army commanders in the pre-war years.

In August 1941, Karbyshev suffered from post-concussion syndrome in combat at the Dnieper River in what is now the Shklow Raion, Mogilev Region, and while unconscious was captured by the Nazis.

Karbyshev was held at a succession of concentration camps, including Hammelburg, Flossenbürg, Majdanek, Auschwitz, Sachsenhausen and, in February 1945, Mauthausen.

Refusing repeated offers from the Nazis to solicit his cooperation, and despite his advanced age, he was one of the most active leaders of the camp resistance movement.

According to the literary testimony of a camp survivor, Karbyshev stayed upright facing his executioners and shouted encouragements to his fellow prisoners.

[4] While in Belarus, in 1916 Karbyshev married again a military nurse Lidiya Vasilyevna Opatskaya (1891–1976), who outlived her husband by 30 years.