In 1849, (on the occasion of the war with Hungary) he was on a march of guards to the western borders of the Russian Empire and on December 6 of that year was promoted to second lieutenant.

On December 6, 1859, he was appointed adjutant wing and on March 14, 1862, he was enrolled in the retinue of His Majesty with deduction from the regiment, on April 17 of the same year he was promoted to captain.

He fought near Plevna on the Grivitsky redoubt, then was on reconnaissance of passages through the Balkans and distinguished himself in the detachment of General Kartsov in capturing the Troyan pass from the battle.

For the difference when crossing the Balkans Tatishchev March 5, 1878 was awarded the Order of St. George 4th degree "While taking possession of the Trojan pass, December 26, 1877, commanding the 9th infantry Staroingermanlandsky regiment, led a frontal attack on the enemy's fortified position and took control of the main redoubt and gun, with insignificant losses for us".

On January 1, 1878, for the difference in cases against the Turks, Tatishchev was promoted to major general with admission to the Suite and appointment from March 1 to the disposal of the Commander-in-Chief of the acting army, Grand Duke Nikolai Nikolaevich the Elder.