During the time of the Clone Wars, the Separatist Alliance established a blockade by the Separatist over the planet of Umbara. This was done to stop Galactic Republic troops from landing there. In the early stages of the Battle of Umbara, the Republic Navy broke through the blockade's defensive lines and successfully landed at least one Acclamator-class assault ship.
The blocking force included a minimum of one Providence-class Dreadnought along with at least six Munificient-class star frigates. One of these frigates was destroyed.
As the campaign progressed, the blockade was strengthened with Recusant-class Light Destroyers, Umbaran Support Ships, an additional three Providence-class Dreadnoughts and ten more Munificent-class star frigates. Its responsibility was to safeguard a Separatist Supply Ship, which was eventually destroyed by a squad of clones belonging to the 501st Legion.