PETER I. (1844-1921), first King of the Serbs, Croats and Slovenes, was the eldest son of Alexander Karagjorgjevie, who had been elected as Prince of Serbia on the expulsion of the Obrenovie dynasty in 1842, and was therefore grandson of Kara George, the first leader of Serbian independence. His father lost his throne in 1858, and withdrew to Austria, where Peter grew to manhood. Accused of conspiring against Prince Michael Obreno vie (1868), Prince Alexander transferred himself to Switzerland, and Peter made Geneva his headquarters for many years.
In 1870 he joined the French Army as a volunteer, and served with distinction in the campaign against Germany. In 1876 he joined the Bosnian insurgents against Turkey and f ought under the assumed name of Peter Mrkonjie, leaving behind him a legend which had its influence on the young revolutionaries of a later generation. In 1882 he, the exiled Pretender, and not the newly proclaimed King of Serbia, was invited to attend the coronation of Tsar Alexander III., who resented Milan's dependence upon Vienna ; and it was very largely due to the Tsar's personal influ ence that in 1883 Peter married Zorka, daughter of Prince Nicholas of Montenegro. For a time he lived at Cetinje, but after his wife's death in 1890 he again lived in Geneva.
In 1903 shortly after the murder of King Alexander and Queen I)raga by a military gang, Peter was unanimously elected King of Serbia and though he was gravely embarrassed at home by the political interference of the regicides, and abroad by the odious circumstances to which he owed his accession, he set himself steadily to work for constitutional government, his tact, self effacement and liberal outlook forming a marked contrast to the attitude of Serbia's previous rulers and contributing to the rapid political consolidation which followed the upheaval of 1903. In June 1914 ill-health forced him to entrust Crown Prince Alexander with the regency, and condemned him to a passive role during the World War. But the simplicity of his life, his stirring procla mations to his soldiers and the visits which he paid to the trenches in a half crippled condition, did much to encourage Serbian resist ance; and he shared the privations of the great retreat across Albania, lying in a litter. After the war and his election as "king of the Serbs, Croats and Slovenes," he lived mainly in retirement at Topola and died on Aug. 16,1921. (R. W. S.-W.)