This second volume of the author's biography of Chaim Weizmann concentrates on the years from 1914 to 1922, when Weizmann capitalized on his scientific achievements to become an "insider" in his relations with prominent British politicians. He was thus in a position to lobby for British support for the idea of a Jewish homeland in and Palestine. With the success of the 1917 Balfour Declaration to his credit, he became the leading figure in the Zionist movement, and from this position worked hard, in tandem with the British, to achieve his goals. More statesman than politician, Weizmann was often autocratic, elitist, condescending in his views of Palestinian Arabs, overly sensitive to slights and dismissive of his rivals. But he was masterful in his dealings with those who had the power to help or obstruct his quest for a Jewish state. He may not always have convinced his British interlocutors to become Zionists, but he usually persuaded them to become "pro-Weizmannites." The establishment of the British mandate for Palestine, incorporating the Balfour Declaration, is the end point of this volume. This masterful study is based on immense research, is gracefully written, and sets the stage for another volume on Weizmann's later years. The tone is admiring, although not reverential, and the scholarship is solid. The surprises come in the details, not in the overall picture of the man and the era.