Valerian of Guernicus
Valerian is a canon magus from the Normandy Tribunal (L&tL p. 137). At age 63 (apparent age 42) in 1205, he is an expert in Terram and one of the best hoplites in the Tribunal. Member of a mystery cult that allows him to bind a spirit as a familiar, he has not passed that knowledge on to Regulus. Valerian is currently a magus of Confluensis, at the Normandy Tribunal.
Since Regulus' bad choice of words in the Tribunal of 1200 he has been a thorn on Regulus' side. A loved thorn, but still a thorn. He will disagree with Regulus' agenda of granting more rights and compensating apprentices for damages because he thinks that is a personal attack.
At first Regulus thought he deserved it, but since it became clear that his pater is not open to apologies and won't try to understand Regulus' side, he decided to fight back and make Valerian acknowledge him by force, building his Hermetic Prestige to the point were he can make himself heard.
Valerian will probably try to move things so that Regulus fails his cases and investigations, or is met with strong opposition. But he (probably...?) won't intervene in a way that jeopardizes serious cases (except for, maybe, trying to put another person to investigate instead of Regulus).
Other People in Regulus' Life:
Argos
Regulus found him trying to survive after the fall of Constantinople, a mischievous child with a penchant to stealing. With some luck he will become a better man. Probably won't be the most liked kid in the covenant.
Sofia
A Redcap from the covenant of Alexandria, in the Theban Tribunal. She and Regulus had a romantic relationship for a couple of years, but it ended when he left Thebes and went to Tugurium. Their story has ended...ish. She could end up appearing again, but probably not.
Maybe Regulus will write her from time to time. He doesn't know yet.
They parted a bit hurt, but in good terms.
Magi and people from Polyaigos
Regulus made a few friends in Polyaigos. Of particular note are Ioannes of Bonisagus (a Trianomae) and Maria Laskarina of Guernicus (a hoplite and Terrae-Magus, just as his pater).
Nicodemus is an old mundane teacher who has taught him both Greek and the elusive art of teaching, and for whom Regulus holds much respect.
He intends to keep in touch with them.
Gifted children of Polyaigos
Regulus met a few gifted children in the covenant of Polyaigos, in Thebes, and taught them for a couple seasons. They are to be presented to the magi of Thebes and taken as apprentices in 1207.
He has no connection with them at the moment, and doesn't intend to keep in touch.