The Five Hundred Worlds Ultramar

The Five Hundred Worlds of Ultramar are Guilliman's empire-within-the-Imperium in Ultima Segmentum, a civilised neighbourhood of systems rather than a single planet. This map files the realm as a sector under a mashed Ultima parent; the researched Ultramar Sub-sector pin already holds the administrative cube.

Macragge, Calth, Konor, Iax, and Espandor sit inside the same civil idea: Tetrarchs, auxilia, and a defence fleet instead of one fortress-monastery. The Great Crusade grew it; the Shadow Crusade and Ruinstorm nearly cut it; the Plague Wars tested whether a resurrected primarch still knew how to govern.

Ultramar still matters as the named Five Hundred, not a random hive cluster. Unofficial summaries keep the existing parent, refuse to treat this pin as Macragge itself, and leave ultramar-subsector as the sibling cube.