This movement began as an extension of a German nationalistic movement in the physics community which went back to the start of World War I with Austria's declaration of war on 28 July 1914. On 25 August 1914, during the German Rape of Belgium, German troops used petrol to set fire to the library of the Katholieke Universiteit Leuven. The burning of the library led to a protest note which was signed by eight distinguished British scientists, namely William Bragg, William Crookes, Alexander Fleming, Horace Lamb, Oliver Lodge, William Ramsay, Lord Rayleigh, and J. J. Thomson. In 1915, this led to a counter-reaction in the form of an "appeal" formulated by Wilhelm Wien and addressed to German physicists and scientific publishers, which was signed by sixteen German physicists, including Arnold Sommerfeld and Johannes Stark. They claimed that German character had been misinterpreted and that attempts made over many years to reach an understanding between the two countries had obviously failed. Therefore, they opposed the use of the English language by German scientific authors, editors of books, and translators. A number of German physicists, including Max Planck and the especially passionate Philipp Lenard, a scientific rival of J. J. Thomson, had then signed further "declarations", so that gradually a "war of the minds" broke out. On the German side it was suggested to avoid an unnecessary use of English language in scientific texts (concerning, e.g., the renaming of German-discovered phenomena with perceived English-derived names, such as " X-ray " instead of " Röntgen ray"). It was stressed, however, that this measure should not be misunderstood as a rejection of British scientific thought, ideas and stimulations.