The D class after Jutland

Two explanations account for the class's origin. One is the Royal Navy's post-Jutland reassessment of whether the C class was good enough; the other is an early-1916 intelligence report that Germany might build light cruisers with ten or twelve 150 mm guns. Broadside geometry mattered more than the headline count because only two German weapons were expected on the centreline while the rest were divided between the beams. The resulting Wiesbaden, Königsberg, and Cöln classes carried eight guns but could bring only about five to bear on one side, whereas British centreline layouts used fewer weapons more efficiently in a broadside. Beam mountings could engage targets on both sides, but they left guns idle against a single opponent. British design reassessment and intelligence about German replacements for lost light cruisers therefore appear as complementary pressures, and historians may weigh them differently.