It consisted of two vessels, Erebus and Terror, named after the two ships lost in the Franklin Expedition.

Both were launched in 1916 and saw active service in World War I off the Belgian coast.

The class was to see most of its service for shore bombardment (naval gunfire support, "NGS") role.

Erebus participated in the invasion of Normandy June 1944 as part of Task Force O off Omaha beach.

Saracen is a fictional account of the service of an Erebus class monitor in the Mediterranean Sea in both World Wars.