The Dido class as screening cruisers

The quoted 1936-37 requirement calls for a small cruiser able to screen the battle fleet from destroyer attack and support flotillas in action. Larger cruisers cost too much and presented unnecessarily large silhouettes for this work. A small screening cruiser did not need the armament required to fight a heavy cruiser. The 5.25-inch dual-purpose gun let the design combine surface firepower with a strong high-angle battery, but the formal case was broader than air defense alone. In this interpretation, calling it a 'screening cruiser' also helped the Royal Navy secure a useful multi-role ship within difficult inter-service and budget politics. As carrier aircraft assumed more reconnaissance work, the requirement placed greater weight on the cruiser's night and surface-screening duties.