On the last day of July 1914, Jean Jaurès, co-founder and leader of the Parti socialiste, section française de l'internationale ouvrière (SFIO), took the short walk from the offices of his campaigning newspaper L'Humanité with a group of fellow journalists to the Café du Croissant for a late dinner.He had just returned from a meeting of the Bureau Socialiste International, the organising committee of the Second International, held in Brussels over the 29 th and 30 th of July, where socialists from all the major European powers, including Keir Hardie, Rosa Luxemburg and Karl Kautsky, had met in an atmosphere of mounting international tension. Austria-Hungary had already declared war on Serbia in retaliation for the assassination of Archduke Franz Ferdinand in Sarajevo, and Russia, keen to increase its power over Serbia at Austria's expense, had started moving a portion of its vast military manpower to the Russian-Austrian border. 1 The comradely greetings exchanged between the delegates in Brussel's Maison du Peuple stood in contrast to the antagonisms that were pushing their national governments to the brink of war, but their public statements reflected the unprecedented nature of the crisis. Issuing an 'Appeal to the British Working Class', Hardie and Arthur Henderson observed that 'for more than 100 hundred years no such danger has confronted civilisation' like the escalating conflict, and closed with an appeal to the virtues of internationalism that socialists had been trumpeting for decades: Workers! -stand together…for peace. Combine and conquer the militarist enemy and the self-seeking imperialists today once and for all.Men and women of Britain, you now have an unexampled opportunity of rendering…a magnificent service to humanity, and the world. 2