I first found out about these books by hearing Rubenstein speak. He is a professor of Conflict Resolution and Public Affairs, and his books focus on the root causes of historical conflicts and the reasons they are so difficult to resolve.
These are conflicts over ideas, and ultimately over belief systems: the 4th-century Christian controversy over subordinationism (called “Arianism” by the winners) and the rationalism inspired by the European rediscovery of Aristotle. The treatments are philosophical as well as historical.