In this paper the author deals upon Masaryk's interest on events in Slavic South of the Habsburg Monarchy in the period from late decades of the 19th century till the Monarchy's collapse. Masaryk endeavored in constraining the spread of German domination across the Balkans towards East, Therefore he considered opposition to the strengthening of the Austrian power in Bosnia and Herzegovina to be important. He criticized Austrian government in Bosnia and Herzegovina not to follow the terms of its military mandate and for not lo let civilian affairs to the Sublime Porte and Turkish legislation. After the Bosnia and Herzegovina’s annexation in 1908, Masaryk put all of his quite a great authority in order to convince the public opinion that with this act of Austrian government an injustice was made towards the people of Bosnia and Herzegovina, for which he belicved to be of Serbian nationality. He attempted to prove 1) falsity of lhe charges against a group of Serbs and Frano Šupilo at tlie higli Ireason proecss licld in Zagreb in 1909, and 2) ineorrcctncss of Viennese professor Friedjung's anti-Scrbian writing. Since then Masaryk's pro-Serbian attitude strengthened, which would later display its uncritical character - especially during the war - denying the importance of Croatian question. His attitude of nation - as a cultural and civilizational community of one or more closely related languages - was a basis upon which lic treated Croats and Serbs, as well as Slovenians, as the same nation, for which he most frequently used the term "Yugoslavs". Part of Croatian and Serbian student youth in 1890s accepted Masaryk's pre-war philosoplhically polilical suggestions for improvement of democracy and for introduction of socially liberal model - with respect of ethical norms, as well as his interpretation of nation as a culturally-civilizational community. His explanation of a phenomenon of a nation was accepted by Yugoslav unitarist-nacionalist youth's opinions. Croalian polilical parties did not accept Masaryk's attitudes. They based the idea of establishing their own nation upon the historical arguments of public law. Although Stjepan Radić separated wilh Party of Rights groups' ideas and showed certain understanding for Masaryk's thoughts, nevertheless he was not a Masaryk’s follower, espccially after he had turned towards the strengthening of a peasant class. Mutual dislike betwcen Masaryk and Croatian politicians in emigration - as a result of above mentioned reasons - strengthened during the World War I. Although they all worked on destroying the Monarchy and on arffirmation of "small nation" rights on state independence, Masaryk justly estimated that Yugoslav nations - parts of Austro-Hungarian Monarchy- could leave the Monarchy only if ihey would join themselves with Serbia. Masaryk considered Croato-Serbian conflicts to be a threat for a realization of that aim. Thus he asked the weaker side, the Croatian one, to give up its special demands.
