He served 20 years (1862–1882) as the Governor General of Caucasia, being seated in Tbilisi, the town which most of his children remembered as the home of their childhood.

In the Russo-Turkish War (1877-1878), he was nominal Commander-in-Chief of the Russian troops in the Caucasus and was appointed Field Marshal General in April 1878.

In the course of his life, four members of his family ruled as Emperors of Russia: his father, Nicholas I; his brother, Alexander II; his nephew, Alexander III; as well as his grand-nephew, Nicholas II, whose second daughter, Grand Duchess Tatiana, the Grand Duke was godfather to.

He was an old gentleman of great height and unforgettable elegance; he fascinated us by the perfection and harmony of his gestures, by his affability and his air of a grand seigneur of an epoch already vanished.

He was the last of the Grand Dukes who, according to the custom of my grandfather's time, tutoi-ed the men, and in spite of his age he bowed with touching grace before the women as he kissed their hands.