I wanted Historical Fiction that wasn’t set in the Civil War, or the 20th century - and Cornwell delivered. And it’s a 13 book series to boot! Next book is on hold from the library. 
It’s 867 and England is not a unified country. Uhtred tells us his story. Born a second son to an Earl - he is destined to become a priest - until a Danish warrior brings the head of his brother back and tosses it on the ground, declaring to Uhtred’s father and his men that the Danes are in the land and intend to stay. At a battle a few years later, Uhtred is 10 - and spies Ragnar, the man who be-headed his brother. Uhtred attacks him with his small sword, and Ragnar reacts by laughing and taking Uhtred hostage. Uhtred lives with the Danes, learns their ways, declares he is Danish and serves with Ragnar. But his heart remains with his homeland, he returns to Alfred’s service.  
Yes, the book has lots of battles, but the battle scenes are well written, and include strategy sessions and even some intrigue. 
One question, how have I never come across the term Shield Wall before?