The Hundred Years War Vol.1 — Jonathan Sumption

The first volume of Sumption's monumental four-volume history covers the origins and early decades of the war, drawing on an extraordinary range of French, English, and other primary sources. The scale and density of the research are immediately apparent, but the book reads as narrative rather than reference — Sumption is a former barrister who knows how to build a case. For anyone serious about the subject, there is no substitute.