After our invasion on Coruscant, the New Republic Defense Fleet has suffered a major blow to its fleet. James says he estimated that 75% of their fleet was protecting the planet and since our invasion, the New Republic cowards remain weak in their own defense!
—Annabelle on the New Republic in the Core Worlds
Following the invasion on Coruscant, the Nakamura Empire fleets had spread out to various planets in the Core to defeat the New Republic while a select few planets were chosen to be swept for Leia Organa, New Republic's Chief of State at the time.
By 31 ABY, the New Republic Defense Forces in the Core were all defeated and Nakamura Empire had full control over the region. Shortly after, fleets of no more than three warships were stationed at various planets as most were being organized into an assault fleet by Supreme Commander James Lovegood for the assault on Mon Calamari.