A History of the Crusades by Steven Runciman
Volume One: The First Crusade and the Foundation of the Kigdom of Jerusalem, 377 pages with black and white photographs.
Volume Two: The Kingdom of Jerusalem and the Frankish East 1100-1187, 522 pages with a foldout Appendix of Genealogical trees., the Royal House of Jerusalem: counts of Edessa: Lords of sidon and Caesarea.
Volume Three: The Kingdom of Acre and the Later Crusades, 529 pages and includes foldout Genealogical trees of the House of Jerusalem and Cyprus and House of Ibelin, a foldout map of Outremer in the 13th century, and black and white photographs. This volume was reprinted with corrections in 1955.
These books are sold as a 3 volume set, not individually.