Lord Solar Leontus

Arcadian Leontus is the current Lord Commander Solar, a Terran highborn who treats Segmentum Solar as a perimeter that has to be defended well beyond its border. He rides the cyborg stallion Konstantin, keeps a court of tarot-readers and logisticians, and has won enough political fights with admirals to keep the title from being ceremonial.

He cites Macharius as precedent for campaigning far from Terra and used the Phalanx as a headquarters when Hive Fleet Leviathan came for Bastior. Valoris has had to pull him out of the fire. Guilliman has had to live with his interpretations of orders.

The remit is Segmentum Solar. The practice is wherever Leontus can argue the Throne is threatened. He is very good at that argument.