The far future setting has the vast galaxy divided into holdings by noble families, organized into Houses, due to a combination of a significant time without Faster-Than-Light travel sufficiently speedy to enable the sort of casual travel common people enjoy today on Earth and a similar lack of tele-communications technologies that allow vastly-distributed populations to interact as if living together. It is during this time that the Church returned to prominence as an institution, deliberately moving itself into the central Axis Mundi, filling the conceptual and political space usually taken by secular hegemons, again- successfully, this time.
The Church owns the entire solar system where Earth--still center of Christendom--and rules it directly, a deliberate revival and upscaling of the old Papal States. Possessed of all the Church's archives, the lessons of past mistakes get avoided by the Papacy of the post-Apocalyptic era, allowing for new ones to occur instead.
With an upscaling of the Papal States comes an upscaling of the Swiss Guard. In addition to the deliberate revival and reinvigoration of the old military orders, the Swiss Guard also came into the new age with a revitalization on their core purpose of protecting the Papacy and acting as the Vatican's armed guard. The Guard became the Solar Guard as the Church expanded into space and assumed ownership of the system, with additional duties including supervision of the military orders. As the years wore on, practices that began as pragmatic necessities became political policies, such as the shunning of noble-born recruits in favor of common-born and the right to claim orphans as wards of the Church.
Today, well into the future, the Solar Guard represents the Church, the Pope, and the Court of Stars. While not a monastic order as such, its long association with the monastic orders (military and otherwise) as well as the Church in general means that certain norms of military life in noble houses are believed--but not required by Church law or Guard regulation--to be for retirement, such as marriage and family life. Instead, the Guard is regarded as a fraternal military order of Knights-Errant; a life of military service directly to all Mankind via the Church, and a knighthood to go with it, but to wait until one's adventuring days close to enjoy the joy of family life- thinking that any foes of a Knight of the Guard are long rendered moot by then, and so avoiding the vulnerability that a heroic knight has in love and fatherhood.
This is a long-standing dispute within the Guard and the wider Church, citing both examples both historical and mythical in the arguments that fly back and forth--yes, including Star Wars--to no decisive conclusion as yet. As our story cycle opens, one such senior Knight of the Guard (Sir Ramsey Hennepin) travels on dispatch from the Court of Stars in Rome on Earth to the distant world of Gamil's Gate due to the depredations of Red Eyes and his pirate fleet, where the dispute (and other issues) will seem so far away.