The Society Remnant is the 'legitimate' successor of the Society, being comprised of the inner worlds and the Gold Houses that remain on these planets or in exile from their homes. The state is officially led by the Ash Lord, as Dictator, until his death at the hands of Darrow and his Howlers (though Atalantia au Grimmus was actually leading for several years before this event) and is then officially led by Atalantia during the events of Dark Age. The Society Remnant has been at war with the Republic for the last ten years and is seen to be losing prior to Dark Age, losing Earth early on in the conflict and Mercury just before Iron Gold.
During Dark Age, the Society Remnant lays siege to Mercury and fights a bitter campaign against from orbit, blockading the main cities and launching an Iron Rain as their leadership forges and alliance with the Moon Lords on board of the Annihilo. The war on Mercury ends with a decisive victory for the Society, thanks to the efforts of Lysander au Lune, and subsequently goes on to reconquer Earth.