I am currently reading NAM Rodger, THE COMMAND OF THE OCEAN, the second volume in his naval history of Britain, which covers the years 1549-1815. In his foreword, the author actually warns that he is concerned about writing a book largely based on secondary sources but fortunately Rodger is a master of his subject matter and has produced a title that can only be regarded as "definitive" for its subject and that is not a word I throw around loosely.
I think this is a brilliant book and one that should be on the bookshelf of anyone interested in the Napoleonic period as it traces the origins of British naval mastery and, in doing so, the difficulties and decline of Dutch, French and Spanish seapower during the 18th century and up to 1815. Rodger's book concentrates less on operational matters than on administration and personnel and he delves into subjects that are important but often overlooked: administration (finance, construction, victualling) and personnel (recruiting, sustaining and training). Above everything else, including geography he emphasizes that Britain's capacity to raise revenue throughout the period was the indispensable foundation of its sea power and it was Britain's economy that made it great.
It always comes down to money in the end. Highly recommended and a model of how secondary sources can be used to produce important new work.
DE Graves