During the Battle of Moon Sound in 1917, Slava was badly damaged by the German dreadnought SMS König, significantly increasing her draft.

At full load she carried 1,350 long tons (1,372 t) of coal that provided her a range of 2,590 nautical miles (4,800 km; 2,980 mi) at a speed of 10 knots (19 km/h; 12 mph).

This was graphically demonstrated when Slava's sister ship Imperator Aleksandr III made a high-speed turn during her trials, heeling 15°, and began taking water through the lower casemates.

On one of her training cruises to the Mediterranean, her crewmen rescued survivors during the 1908 Messina earthquake and the ship took casualties to Naples for medical care.

[6] The Baltic Fleet only had four pre-dreadnoughts in service, as the Second Brigade of Battleships, when World War I began, although the four dreadnoughts of the Gangut class were almost finished.

More specifically she was to support the Imperial Russian Army with her guns and to defend the gulf against German naval forces.

[7] Barely a week later, on 8 August, the Germans began to sweep the mines defending the Irbe Strait, and Slava, accompanied by the gunboats Khrabry and Groziashchii, sortied to fire on the minesweepers.

The German pre-dreadnoughts Elsass and Braunschweig attempted to drive the Russians off, but Slava remained in position despite sustaining splinter damage from near misses.

During one of these missions, as she was bombarding German positions near Tukums on 25 September 1915, she was hit in the conning tower while at anchor, killing her captain and five others.

She continued to support the Army until the water in the Gulf of Riga threatened to freeze over at which time she retired to the port of Kuivastu to winter over.

On 2 July she resumed her support of the army with a bombardment of advancing German troops despite sustaining one hit by an 8-inch (203 mm) shell on her waterline armor that caused no damage.

[18] Slava was held back during the initial stages of the German landings (Operation Albion) on Saaremaa (Oesel) Island guarding the mouth of the Gulf of Riga in October 1917 to defend Kassar Wiek (Inlet), which separates the outer islands of Saaremaa and Hiiumaa (Dagö).

She intermittently fired at German torpedo boats as they fought Russian light forces in Kassar Wiek on 15 and 16 October, but scored no hits from her position near Kesselaid (Schildau) Island in Moon Sound Strait.

[19] On the morning of 17 October the Germans attempted to sweep the Russian mines placed at the southern entrance to Moon Sound Strait.

Slava, the pre-dreadnought Grazhdanin and the armored cruiser Bayan were ordered south to meet them by Vice Admiral Mikhail Bakhirev, opening fire on the minesweepers at 8:05 a.m.[Note 2] The dreadnoughts König and Kronprinz were to provide cover for the minesweepers, but Slava, sailing further south, opened fire on them at 8:12 at nearly her maximum range.

[20] The German minesweepers made good progress, despite minor damage from shell splinters and numerous near misses by Slava, Grazhdanin, Bayan, and the Russian shore batteries.

Slava and her consorts were ordered north to allow the crews to eat lunch, but returned to the fray and opened fire on the minesweepers again at 10:04 with her rear turret at an approximate range of 12,000 yards (10,973 m).

They damaged a six-inch magazine and the forward stokehold (boiler room) and started a fire which was put out after about fifteen minutes.