The design was originally proposed as a replacement for the Champion class in 1864 PD. It was just as missile heavy as the contemporary Bastogne class destroyer, but corrected some of that class' shortcomings by implementing a lighter broadside throw weight in favor of larger magazines.
The Sword class was also the only class of Havenite warship regularly equipped with the LMF-5(c) missile tube, designed for high speed loading. (JIR2)
Once in service, the Sword class proved to have serious problems due to its limited counter missile firing capabilities; a captain had to bring his ship in and destroy the enemy before the latter could overcome the ship's weak defenses. A number of refits were tested to overcome these flaws, the one on PNS Flamberge being considered the most successful. (JIR2)