The six volumes of A History of the Crusades will stand as the definitive history of the Crusades, spanning five centuries, encompassing Jewish, Moslem, and Christian perspectives, and containing a wealth of information and analysis of the history, politics, economics, and culture of the medieval world.
This is the third in a very scholarly series on the crusades. It covers the final era of the Crusades as well as the Spanish Reconquista, the Teutonic German Crusades, and the "crusades" against the Hussites. Of special interest here is the siege of Malta which broke the back of the faltering advance (that had already been doomed to fail after Venice). Unfortunately, this book failed to elaborate in-depth on how much those two failed sieges spelled the end of Islamic military supremacy. It also fails to mention how, by the late fourteenth century, the Islamic world was already beginning to fall behind technologically. There is the occasional mention of hiring this or that European to build for them canons, siege weapons, etc. but no significance was put to why they were not developing internally such individuals who could invent or utilize the newest advances. This is a significant piece of the faltering of the Islamic conquests, but it is completely ignored.
In all, many of the same strengths and weaknesses mentioned earlier in my reviews of Volumes 1-2 stand true here. There technically is a fourth volume to this set but since it mainly deals only with the art and architecture, I'm going to skip it. I would recommend these books for someone who already has a strong background in the Crusades, but they are certainly not entry-level. Runciman is still the standard for the History of the Crusades even though he is strongly biased.