Edgar, Powerful, Diadem and Cressy Class first class cruisers

The Edgar Class first class protected cruisers were the oldest British first class cruisers to see active service during the First World War.
The two Powerful Class first class protected cruisers were built in response to the public reaction to the rumoured capacity of two new Russian cruisers, the Rurik and the Rossiya.
The Diadem Class first class protected cruisers were smaller, more successful, versions of the Powerful class ships.
The Cresy Class first class armoured cruisers represented an important step in the process that eventually led to the production of the battlecruiser.