The Hundred Years' War is misnamed twice over: it ran longer than a century and it was really a series of wars, truces, and renewals between England and France. That messiness is why readers get lost. Reading it in order, from a vivid overview to focused studies to the definitive histories, keeps the long arc in view.
The path opens with the world the war belonged to, narrows to its decisive figures and battles, and ends with the scholarship that maps the whole conflict.
The world and the overview
Start with A Distant Mirror by Barbara Tuchman, which uses one nobleman's life to paint the calamitous fourteenth century of plague, war, and upheaval; it is the best way to feel the era before tracking the campaigns. The Hundred Years War by Desmond Seward then gives a brisk, readable narrative of the whole conflict, a reliable spine for everything that follows.
Kings and decisive battles
The war turned on a few people and a few fields. Henry V by Christopher Allmand is the authoritative life of England's warrior king, and Charles VII by M. G. A. Vale recovers the French monarch who eventually turned the tide. For the war's most famous clash, Agincourt by John Keegan analyzes the battle with his signature focus on what combat was actually like, while Agincourt: The King, the Campaign, the Battle by Julian Rathbone offers a fuller campaign narrative. Medieval Warfare by Helen Nicholson supplies the wider context of how such armies fought.
Joan of Arc and the definitive histories
No account is complete without Joan. Joan of Arc by Helen Castor is a superb modern life that restores her to her own time, and The retrial of Joan of Arc by Regine Pernoud draws on the trial records that rehabilitated her. To go all the way in, The Hundred Years War by Jonathan Sumption is the monumental multivolume history for readers who want the full sweep, and England, France and the Hundred Years War by Clifford Rogers gathers the essential scholarly essays.
Read in this order and the war stops being a blur of Edwards and Henrys and becomes a story with shape. Follow the full path to read it end to end.