The long, internecine war in Yemen, begun in the 1990s, has dramatically deteriorated since the publication of the second edition of this reference work in 2009 (CH, Jun'10, 47-5397). Edited by Schmitz (geography, Towson Univ.) and Burrowes, the two major experts on this Arab Gulf nation, this third edition provides updated and expanded versions of the two earlier editions compiled by Burrowes. Among other new material, the third edition contains entries on Houthi and Salafi leaders and the "final dates" of individuals who were still alive in the previous editions. Like other titles in the "Historical Dictionaries" series, this work includes hundreds of entries on individuals, places, events, and institutions. The eclectic scope of the coverage is impressive, ranging from IMF/World Bank aid, monsoons, and water resources to Jews and Judaism in Yemen. An extensive chronology and introduction and an informative bibliography arranged by topic enhance the reference value of this important work, which provides superb background material about this historical yet under-reported nation. Summing Up: Essential. All academic levels/libraries.