This book was produced for Spanish readers with the English text as an appendix at the end.  All the illustrations are in the Spanish part.  Despite this, the English text is well worth reading.
At heart, this is a romance; beginning with Gerald’s captivation with Spain, Estremadura and Badajoz.  Less stated but equally important was his courtship and marriage to a Pacense, as natives of Badajoz are known, and finishing with the charming tale of Harry Smith and Juana Maria de los Dolores de Leon, made famous by Georgette Heyer in her book . “The Spanish Bride”.
However, Gerald went to Spain to study the battles of the Peninsular War.  He not only walked the battlefields, but consulted local historians and spent much time researching at the National Army Museum, Museums of the Royal Artillery, Royal Engineers and the Middlesex Regiment and the British Library in England and the Ayuntamiento de Badajoz and the Museo Arqueologico de Badajoz.  The result is that while he set the scenes, described the historical context and created the atmosphere, the descriptions of the actions are largely from first-hand accounts of the soldiers.  He also quotes liberally from French despatches and reports to give a very good idea of their side of events
Some purists will dispute some of the facts and English readers will find the many typographical errors annoying but for many this is an excellent introduction to that part of Spain and to the history of those important and sanguinary actions.