Having received an excellent education at home and at the Physics and Mathematics Department of Moscow University,[1] Prince Alexey Obolensky passed the officer's exam at the Mikhailovsky Artillery School in 1838.

On April 10, 1848, Prince Obolensky was promoted to staff captain and in November of the same year was appointed adjutant to Grand Duke Mikhail Pavlovich, commander–in–chief of the guards and grenadier corps.

With the beginning of the Crimean Campaign, Prince Obolensky was sent to Novocherkassk to monitor the formation of five Don Batteries, and after that, by order of General Khomutov, he was sent to Sevastopol for reinforcements.

Acting as an aide–de–camp, in 1858, he was also a member of a commission established in Moscow, chaired by Lieutenant General Tuchkov, on the case of unrest and abuse of allowance for the troops of the former Crimean Army, and the following year he conducted an investigation into the causes slow construction of Orthodox churches in the landlord estates of the Vitebsk Governorate.

Two years later he was awarded the Order of Saint Vladimir of the 2nd Degree, and in May 1875, he was elected an honorary magistrate of the Olgopolsky Judicial District of the Podolsk Province.

On January 1, 1881, by the Highest Decree, he was appointed to the presence in the Department of Heraldry of the Governing Senate, and two years later, on May 15, 1883, he was promoted to general of artillery, leaving the prince in all positions held.

[2] From the mid–60s, she lived in Switzerland in a civil marriage with a Polish emigrant Mrochkovsky, under the influence of her husband she became an anarchist, Bakunin and Reclus visited her house.

Their son was Vladimir Obolensky, a prominent figure in the Zemstvo Movement, the Constitutional Democratic Party, a deputy of the First State Duma, a memoirist.