Author of Armies in Revolution (1974) and A Social History of the Machine Gun (1976), Ellis is a military historian who processes enormous chunks of data with the steely efficiency of a compactor. In this not-so-short history he examines no less than 130 guerrilla movements, dating back to the Roman Empire. If nothing else, Ellis' digests--of the Montenegran haiduks, the Maccabees, the Welsh border fighters against the Normans, the half-century rearguard action of the Maya against the Mexican government, the Libyans under Omar Mukhtar, the Seminoles vs. the U.S., the anti-Turkish uprisings in Africa, and the British attempts to subdue Kachin tribesmen in Indochina--must be appreciated as historical exotica. Fie certainly gets across the point that guerrilla warfare didn't begin with the Spanish Civil War. Unfortunately, the conclusions drawn from this morass of material are less than astounding. Ellis notes that few guerrilla forces succeed militarily unless they acquire enough strength to become regulars; generally they function best as ancillaries to conventional armies. Logistically, they need a secure base, preferably in woodlands, mountains or marshes. Most crucial of all is the support of the people at large--Mao won partly because of the remarkable class unity he achieved among various strata of the peasantry. Though Ellis makes some useful distinctions between the many historical types of guerrilla forces--the politicized banditry of Mexico, the predatory marauding warfare of the Huns and Magyars--he dismisses urban fighters like the IRA or the Tupemaros as instances of ""half-baked gangsterism."" A curious omission, considering the overall eclecticism of the book and the current news from Lebanon.