The origins of the Sovereign class date back as far as 2338. At this time relationships between the Federation and the Klingon empire had degraded significantly, to the point where war was considered by many to be imminent.6 The President ordered Starfleet to place a design proposal for a new class of starship with very much greater military capability than current designs. This project was in the advanced planning stage when the loss of the Enterprise-C during the Narendra III incident eased tensions considerably.6 The warship project was initially to be scrapped, but Starfleet was instead asked to continue the project on a research basis only. Dubbed the Sovereign project it became a theoretical starfleet battlecruiser designed only as a computer model, with specimen hardware occasionally produced to test the design principles. The intention was to create a design that could be put into production with no delay, should a future crisis present itself.
Source: Daystrom Institute Technical Library
