Gilbert, a British historian knighted for his work, which includes a multivolume biography of Winston Churchill and a comprehensive history of the Holocaust, presents a year-by-year account of the era 1900-1933. This first of three volumes spans the years from the end of the Victorian era to the inauguration of Franklin D. Roosevelt. The years leading up to and including WWI receive major attention, but the author does not neglect such other watersheds as the rise of Hitler, Mussolini and Stalin. Mingled with the wars, assassinations and national confrontations of the period are the more constructive developments--the wireless, internal combustion engine, air travel. Myriad sources include standard fare--reference books, newspaper quotes, diplomatic documents--but also private journals, diaries and even novels and poems. This, plus a strong narrative style, helps to elevate this title above the dry and dusty lengthy historical treatise. Photos not seen by PW. Author tour. (Nov.) FYI: See review of another Gilbert book below.