The Evstafi class were a pair of pre-dreadnought battleships of the Imperial Russian Navy built before World War I for the Black Sea Fleet. They were slightly enlarged versions of the Potemkin, with increased armour and more guns. Numerous alterations were made as a result of experience in the Russo-Japanese War of 1904–5 that seriously delayed the completion of the two ships.

The 12-inch 40-caliber naval gun was the standard main weapon of the pre-dreadnought battleships of the Imperial Russian Navy. Sixty-eight guns of the first production run were built in 1895–1906 by the Obukhov Works in Saint Petersburg. They were installed on seventeen battleships starting with Sissoi Veliky and Tri Sviatitelia and ending with the Andrei Pervozvanny class. A second production run was ordered to Russian and British gunmakers during World War I.