Pre-dreadnought is awkward because it defines a period by what came at its end. Taken literally, the label could include HMS Victory, the first-rate ship of the line Nelson commanded at Trafalgar, even though that is far broader than normal naval usage. Period names usually take their cue from the beginning, which leads to the joking proposal that these battleships should be called Royal Sovereigns instead. During World War I, people needed a catch-all distinction between dreadnoughts and older battleships, and pre-dreadnought supplied it. The label persisted, leaving historians either to accept it or keep objecting to its backwards logic.
Notable Point · 1:34-2:44
Why pre-dreadnought is a backwards-looking label
Pre-dreadnought defines older battleships by HMS Dreadnought, which came at the end of the period, but World War I usage made the catch-all term durable.