This book - the first in a series of four - brings together a sketch of Anarchist organisation and perspectives in the twentieth century. Anarchists and syndicalists were centre stage in the history of labour movements in much of `Latin' Europe and in most of Latin America in the first two decades of the twentieth century. Syndicalists and libertarians sought to develop solidarity and workers' power, rejecting both cautious and conservative trade-unionism and their allied socialist parties. Criticising the chauvinism that engulfed the Second International and its most powerful section, German Social-Democracy, they campaigned for class solidarity across frontiers and worked to subvert the discipline that bound soldiers to imperialist states. The second part of this book describes international and national campaigns against militarism and war. Libertarians investigated democratic, modern and scientific ideas and challenged obscurantist, religious and authoritarian conventions. They sought to focus and organise the strength of working people whose voices could not be registered in parliamentary politics, working at a time when many working people had no right to vote, and also sometimes, challenged patriarchal gender relations. This is the first of four:1. Anarchist Perspectives in Peace and War, 1900 -19182. Anarchist Perspectives: Syndicalism, Revolution and Fascism, 1917-19303. Anarchist Perspectives: Revolution in Spain, 1931-19394. Anarchist Perspectives after the Second World War