I won't bother going too deeply into the story line or specific characters as you can read that in depth in a bunch of other reviews. Instead I'll talk about what type of book this is.
The Prince of Nothing series (I have read the first two) is in my opinion a combination of elements from many fantasy settings such as Dune, Tolkien, Martin and Erikson but done in such a way as to be completely fresh and often elevated in its ambitions above those others. It truly seems as if these books are trying to do more than just tell us a good story.
As with the Dune series and Erikson's Malazan books you start off almost completely like a fish out of water. Various factions, schools, countries, titles, characters and new words hit you like a steady stream. For me personally, part of the enjoyment with these types of books is discovering and learning the culture and world in which their characters live. It is obvious the author did much work on developing huge aspects of his fantastical setting prior to completing the first book. Much like Tolkien's Middle-Earth, I imagine you could write whole volumes on just the back-story and history of the setting in which this series of books takes place. Hopefully one day Mr. Bakker may treat us to more glimpses of this well-crafted and unique world.
The plot, which unfolds in this well-crafted setting, is reminiscent of the G.R.R. Martin's books and other political fantasy in that the majority of the book's conflict is driven by political and personal conflict between the many factions and cultures versus a traditional good versus evil. Although there is a quest of sorts (a holy crusade against the heathens) that forms the framework for the flow of the story it plays only a background role. The real story is the development and interplay of the characters and the figurative paths they embark on over the course of their literal journey to the Holy City. "The Darkness that Comes Before" focuses on the introduction and bringing together of the main characters, sheds light on the ambitions of the various factions and shows the preparations of the holy war. The second book, "The Warrior-Prophet", focuses on the travels and trials of the characters and the holy war as they march and fight across the heathen lands. And I imagine the last book will most likely focus on the climax of the war and the lead character's ambitions, all of which need to take place at the destination itself of the holy war. All roads lead to Shimeh!
Make no mistake this is NOT a light read and I often found myself having to read very slowly and carefully as much of the prose requires a good visualization and attention to nuances. Fortunately now that the last book in the trilogy is about to be released readers can and should read the trilogy beginning to end so that the complexities of the story can be maintained and very few of the nuances of the story will be lost.
The Prince of Nothing series abounds with philosophical, political and religious overtones and shows how all three often overlap and how they play together - not altogether completely without relevance in today's world. Indeed the religious and political aspects often serve for much of the philosophical arguments posed and pondered over the course of the story. About the only negative from my perspective was that on a few rare occasions the story bogged down in what felt like a thinly veiled philosophical debate about certain aspects of human nature and the forces that govern us. Thankfully the story is so intriguing that these rare and momentary slow downs were easily forgiven and were really not that surprising given the fact that the author has an advanced degree in philosophy.
In summary, this is a very well crafted and well-written book that demands a lot of its readers. It will however reward those who put in the effort with a unique, complex and fulfilling story. It abounds with extremely deep, believable characters, just enough fantastical aspects to keep it refreshing and interesting, a good deal of conflict and action and maybe just maybe might cause you to wax philosophical from time to time. After all, what is this "Darkness That Comes Before" that causes us to do the things we do and believe the things we believe?