Following their victories during Operation Uroboros and at the Battle of Jachin Due, ZAFT sought to remove the Earth Alliance from space entirely and destroying Alliance military targets such as Ptolemaios lunar base and Endomiyon resource base.

On May 3rd, ZAFT forces defeated Alliance defenders and made landfall on Luna, soon they constructed a base in Lorentz crater to serve as their beachhead. From there, they would continue their offensive on the Moon, eventually dividing the Moon in Alliance-held and ZAFT-held sides, divided by the Grimaldi crater, soon to be known as Grimaldi front.