The Primordial deities or "Protogenoi" were the basic components of the universe which were emerged at creation. They included earth, air, sea, sky, water, underworld, darkness, night, light, day, procreation and time. They are among the most powerful beings in all of creation, rivaling even the archangels in power and strength. Although they are still relatively weak when compared to God.
As the first born of the immortals, who formed the very fabric of the universe, they were primarily known in Greek mythology as the Protogenoi (protos meaning "first," and genos "born"). They were, for the most part, purely elemental beings; example such as Ouranos being the Sky and Gaia being the Earth. A few of them were occasionally described or portrayed in anthropomorphic form, however these forms were inevitably inseparable from their native element.
During the collision between God and Chaos, the resulting implosion of their divine power resulted in the creation of the primordials. And after Chaos was defeated and imprisoned, God then turned His attention to these primeval beings. The archangels at first opted to destroy them in fear that they might turn against them just as the Outer Gods did, but God refused for He noticed that despite being born out of the chaos that molded with life, they were rather benevolent, and thus spared them.
Seeing that they embody the components of creation itself, God assigned them with becoming these very components once the universe and all its concepts were done in order for the "natural wheel" to spin in a stablized manner. The Primordials agreed and carried on with this task. Once complete, they laid dormant in their natural state for many centuries and in the process gave birth to other primeval deities. To this day they remain inactive and take no part whatsoever in the events that transpire concerning the mortal realms, for they are one with the forces and concepts they embody.
It is generally believed that the Primordials represent the "light" of creation while their counterparts the Outer Gods represent the dark. However, unlike the Outer Gods, the Primordials were not used as tools of destruction during the war against Chaos. There is much debate on how the Primordials were truly created, either by Chaos or God's power. However, seeing as though that Chaos was bent on nothing but the destruction of all things, it is safe to assume that the Primordials were created largely by God's power during the clash.