**A Foreign Affairs Best Book of 2022** In 1935, Fascist Italy invaded the sovereign state of Ethiopia — a war of conquest that triggered a chain of events culminating in the Second World War. In this stunning and highly original tale of two Churches, historian Ian Campbell brings a whole new perspective to the story, revealing that bishops of the Italian Catholic Church facilitated the invasion by sanctifying it as a crusade against the world's second-oldest national Church. Cardinals and archbishops rallied the support of Catholic Italy for Il Duce's invading armies by denouncing Ethiopian Christians as heretics and schismatics, and announcing that the onslaught was an assignment from God. Campbell marshalls evidence from three decades of research to expose the martyrdom of thousands of clergy of the venerable Ethiopian Church, the burning and looting of hundreds of Ethiopia's ancient monasteries and churches, and the instigation and arming of a jihad against Ethiopian Christendom, the likes of which had not been seen since the Middle Ages. Finally, Holy War traces how, after Italy's surrender to the Allies, the horrors of this pogrom were swept under the carpet of history, and the leading culprits put on the road to sainthood. ‘This stunning book explores the Catholic Church’s support for and encouragement of Mussolini’s campaign against the Ethiopian Orthodox Church during Italy’s invasion and occupation of Ethiopia from 1935 to 1943. … Eloquent and based on authoritative archival research in both Ethiopia and Italy, Campbell’s book sheds new light on a key episode in African history.’ — Foreign Affairs ‘Three cheers for Holy War [which] has turned the caring Italian Army myth upside down and inside out in what is the perfect antidote to Louis de Bernieres’ Captain Corelli’s Mandolin. […] Holy War is the ‘go for’ book if you want to learn as much as you need to know about an invasion that helped shape the rest of the 1930s, a paving stone towards World War in 1939.’ — ColdType ‘This is an immaculately researched book on the composite history of Ethio–Vatican relations in the 1930s. It will hopefully open doors to a desperately needed rapprochement between these two former antagonists!’ — Prince Asfa-Wossen Asserate, PhD, author of King of Kings: The Triumph and Tragedy of Emperor Haile Selassie I of Ethiopia