In 1877, already as a Stabs-Captain, he entered the General Staff Academy, but soon left to take part in the Russo-Turkish War, where he participated in a number of battles, including Tashkessen, Plovdiv and Adrianople, where he was wounded.

After serving in positions of increasing responsibility, including commanding the 93rd Irkutsk Infantry Regiment; he was promoted to major general in 1898, with an appointment as the chief of staff of the 2nd Army Corps, based in Grodno, near the western border of the empire.

[2] After Moscow's Governor General Fyodor Dubasov was wounded by a bomb in April of the same year, Gershelman was appointed as his replacement, taking up this position on 5 July 1906.

During Gershlman's term as Governor General of Moscow, the area under his jurisdiction was expanded, to include not only the city proper but also the adjacent section of Moskovsky Uyezd.

Gershelman's gubernatorial service earned him effusive praise from the local conservative newspaper, Moskovskiye Vedomosti, which was to write later in his obituary (18 November 1910): During the difficult times of the post-revolutionary chaos, [Gershelman] was appointed... to this position of responsibility, and with his indefatigable efforts and unfailing vigilance and energy he maintained strict order in the most difficult circumstances.

Meanwhile, the more urbane Sergei Witte described Gershelman as a "brave general, but without any political culture", and a "spiritual ally of the Union of the Russian People".

Gershelman's horses were killed, but due to the cold weather, the force of the explosive was reduced, and the general himself merely lost the badge from his uniform hat.