The Romulan Enterprise was the massive influx of Romulans into the Semerian Space, namely Border regions, many died during this period due the Semerian's ruthless purgings.
This action was due to a massive population boom on Romulus and Romulan Space in which resulted in overcrowded cities and the loss of jobs. So many people used Starships to explore across the Multiverse to colonized a planet, with plenty of space. A massive fleet of ships set off for the Zi'ki universe, and arrived. Many detours were taken and many battles between the Axis, Alliance and Coalition were encountered, but the ships finally reached an inhabitable planet, with one quarter of the initial number of passengers.
Most explorers headed into the Semerian Space, whereas some went north towards Gormelar Prime, the capital of the Semerian Commonwealth.