She later fought successfully against Bolshevik naval forces during the early months of the Russian Civil War, helping secure the Budjak region.

During the interwar period, she contributed to the suppression of the Tatarbunary Uprising and was rearmed with longer main guns towards the end of the 1930s.

Her bow was fitted with a breakwater, the distribution of her inner cargo was evened to prevent listing, her deck was made waterproof and more instruments required for sea navigation were brought from the cruiser Elisabeta.

During the war, Mihail Kogălniceanu was part of the group of ships ferrying Romanian troops from Corabia to the Bulgarian shore.

The four warships kept Bulgarian and German ground forces under a powerful and accurate barrage of fire, allowing thousands of Romanian troops to escape the encircled city.

As a consequence of this and previous actions at Turtucaia and elsewhere, German General August von Mackensen decided to eliminate the Romanian monitors.

The German batteries fired with intensity, but by the end of the day, all that was achieved was minor damage to one of her sisters, the monitor Alexandru Lahovari, which also had 6 wounded.

[11] At the start of October, rumors about approaching Romanian river monitors caused the Austro-Hungarian naval forces to retreat, thus putting an end to the Battle of Flămânda.

Under intense fire from the Romanian monitors, the Bulgarians temporarily retreated, but soon returned to their positions after the Russians failed to take the offensive.

In the last days of 1916, Mihail Kogălniceanu was at Ismail, covering the vessels which were ferrying the Russians North across the Chilia branch.

[13] After a winter of relative inactivity, the Romanian Navy took some defensive measures as well as performing warship upgrades, the monitors being fitted to fire French 120 mm rounds, which gave their main guns a range of up to 11 km (6.8 mi).

The bombardment caused significant losses, and the monitors fired until all enemy artillery batteries in and around the city were silenced, suffering light damage themselves.

In the morning of 11 November, three hours before the Allied Armistice with Germany was signed, the monitor, together with the 30-ton river torpedo boat Trotușul, occupied the port of Brăila, after the Germans retreated from the city.

The two Romanian warships captured 77 assorted German vessels abandoned in the city's port (barges, tankers, tugs, floating cranes, motorboats).

[21] After the return of the other surviving Brătianu class monitors from the Soviet Union in 1951, it was decided that Mihail Kogălniceanu and Lascăr Catargiu should be refloated.