Very few of the Breton class light cruisers were available in time to see service in the First Solomani Rim War, and consequently the production run was slowed as a result of the end of the war, many examples being scrapped partially completed. Some new construction did continue though at a reduced rate until the Third Imperium began to break apart, at which time construction was accelerated on those vessels not yet completed to clear yards for higher priority work. Bretons were typically employed as small squadron flagships, convoy escorts and as commerce raiders. They had a good maneuver rating at 5G though endurance was somewhat limited when this was employed, but their limited jump range, jump-3 reduced their flexibility.

One division of four Bretons was captured by the Third Imperium during the latter days of the First Solomani Rim War at the battle of Terra. None of them had functioning jump drives. These were taken into Imperial service and served for many years at Dingir before being mothballed.

When the Civil War erupted the Imperials solitary Breton CruDiv was reactivated. They fought heroically, and two, Davenport and Fremantle were re-taken by the Solomani. Davenport was damaged beyond repair during that encounter. Fremantle was repaired and served with others of its type until virus struck. Her fate is unknown beyond that point.

It is believed that a number of Breton class light cruisers are operating in the Banners sector, whether by virus or other entity is not yet known.

Fuel purification equipment (141.875Mw) is sufficient to purifiy 28,375 cubic meters in 6 hours (30 hours for entire load exclusive of power plant fuel) Fuel scoop capacity is 70,000 cubic meters per hour (2.03 hours for entire load exclusive of power plant fuel).