Sarum in Salisbury, England is not for the faint of heart. One of the hard back editions has 912 pages. I listened to it through Audible—45+ hours—of pure enjoyment, and that is hard to say about any book that is 500+ pages. The reader of the Audible edition sounded like Penelope Wilton, the actress who played Isobel Crawley on Downton Abbey.
Sarum recounts the formation of the British Empire from prehistoric times to the year 1985. It is a generation to generation type of book. Given the time period involved, not all characters survive but Rutherfurd incorporates bits and pieces of earlier time periods throughout. It might be a fleeting or subtle reference but each time my memory of what the author was referring to came back in time, except for one time during the ending. The tail end might throw a reader. It did me until I remembered the underlying feud/argument that reaches way back.
Rutherfurd notes in the very beginning that there will be parts that are recitations of history. These parts are relatively small in number and length; the inclusion of these sections helps to move the narrative through certain parts of British history that are accounted for well in books, both non-fiction and fiction, by other authors. Examples are Agincourt, the reign of Henry VIII, and WWI.
An interesting nugget: Sarum was the hidey-hole of Allied forces – all manner of material, people, and equipment was kept there in preparation for D-Day.