If you’re looking for a dynamic and riveting history of the Vikings, this isn’t really it — Neil Oliver’s book might be more your speed. It’s quite slow and thorough, covering a lot of ground in terms of both time and space. For me, that wasn’t a bad thing, since I know my medieval history tolerably well and my Viking history better. A better knowledge of geography might have served me well, but I suck at that.
From all I know, this is well researched and accurate, and there’s a ton of extra reading and footnoting to back that up. If you’re looking for something to bring the Vikings to life, no, but if you’re looking for something by someone who seems to know everything about the period he can find to cram into a book, then that’s definitely this book.