They were squat ships, both commissioned in 1926, with a relatively heavy armament for their size (three 150 mm (5.9 in) Krupp guns, the same type and calibre as for the cruisers Java and Sumatra).

Their main asset was an advanced fire control system that made them very accurate in bombarding shore targets, as a similar gunboat, Johan Maurits van Nassau, demonstrated in 1940 when she silenced a German battery from a distance of some 19 km (10 nmi).

Flores was brought back to the Netherlands at the start of World War II where she patrolled home waters until the Germans invaded in 1940.

Flores and Soemba were united in the Mediterranean Sea and played an active and successful role in the landings in Sicily, Salerno, Anzio, Garigliano, Gaeta and finally, at the beaches of Normandy in June 1944.

With their guns worn out due to intensive use, the two ships were retired from active duty shortly after the war and used for artillery instruction and as floating barracks.