The Captain Flandry Series II

I have argued that, of the seven works in (what I call) the Captain Flandry Series, four form a tetralogy:

"Tiger by the Tail" (1951)
"Honorable Enemies" (1951)
"The Game of Glory" (1958)
"Hunters of the Sky Cave " (1959)

that two form a diptych:

"A Message in Secret" (1959/1961)
"The Plague of Masters" (1960/1961)

and, further, that the tetralogy precedes the diptych, contrary to the order of the stories in Sandra Miesel's Chronology of Technic Civilization.

The anomaly is "The Warriors from Nowhere" (1954). On the one hand, it contains the Hooligan and Chives. On the other hand, it was written before "The Game of Glory," in which Flandry has not yet acquired either a private spaceship or a personal servant. However, Poul Anderson solves this conundrum. Retroactively, the story becomes a prelude to A Knight Of Ghosts And Shadows, the opening novel of the Children of Empire Trilogy. In A Knight..., Hans Molitor has become Terran Emperor after a civil war and, we are to understand, the events of "The Warriors..." occurred during that war, when Hans had not yet defeated all of his rivals but was nevertheless already being served as Emperor by Flandry and others.

Thus, "The Warriors..." becomes the first of four works set during the Molitor dynasty and the entire Flandry series comprises:

the Young Flandry Trilogy;
a tetralogy;
a diptych;
the Molitor period.