This volume includes a long novella by David Weber I Will Build My House of Steel which is a bit under 200 pages, and a number of article by a group known as BuNine on various aspects of the Honorverse, which make up the remaining 300 or so pages.
The story covers the life and reign of Roger Winton, the predecessor to Elizabeth, the present queen of the Manticoran Republic. The story concentrates on his efforts to build up the Manticoran Navy before it faces a war with the Republic of Haven. As such there is little action until the end, and then a final moment of reflection as Elizabeth ascends the throne. Much of the story is concerned, as is the case in much of Weber's later novels, with politics.
The remainder of the book is articles about the history of Manticore and Grayson, a principal Manticoran ally. There is also a considerable amount on weaponry, and alien species, such as, but not limited to, treecats. This part, especially the history will probably be useful as a refresher before reading the next Honorverse novel Cauldron of Ghosts, which is due out this month.
Next up, Condi Rice's reflections on her time in Washington.