The book "Christianity and Islam in Spain, 756-1031 AD." by Charles Reginald Haynes examines a period in Spanish history when Christian and Islamic cultures coexisted in the same territory. The author explores not only the political events of this time, but also cultural interactions, religious syncretism and the influence of civilizations on each other. The book reflects the complex relationship between Christians and Muslims in medieval Spain and helps to better understand the overall context of these historical events. It is not only a valuable source for historians, but will also be of interest to a wide range of readers interested in the study of history and religion.