he Washington Naval Treaty of 1922, signed by the Allied maritime powers, was intended to prevent a naval arms race similar to that which had precipitated the First World War. The treaty restricted the building of capital ships and limited heavy cruisers to a displacement of no more than 10,000 tons. A newly planned class of heavy cruisers to replace the Hawkins class were designed within the constraints of the Washington Treaty, to the maximum displacement and armed with 8in (203mm) guns. Christened the County class, the new cruisers were a fine balance of speed, firepower and excellent sea-handling and
