Military History magazine is the cream of this type of magazine. The magazine is nicely laid out, easy to read, well-written and it covers a wide variety of subjects. There is no particular slant... other than articles written to keep the reader turning the pages.
Over the roughly dozen issues I have seen, there were articles on battles ranging from the American Civil War, both World Wars, Vietnam, various Middle East conflicts, sea/submarine stories, British battles... a great variety. All are thoroughly researched and ring true to my fairly good knowledge of history.
Recommended for at least high school age and from there any history buff would find this magazine interesting.