The Berlin Philharmonic Orchestra [Berliner Philharmoniker] was founded in 1882 and by the end of the 19th century had firmly established an international reputation. Guest conductors in the early years included Johannes Brahms, Edvard Grieg, Gustav Mahler, Hans Richter, and Richard Strauss. Wilhelm Furtwängler (1886-1954), considered one of the greatest conductors of the 20th century, was principal conductor from 1922 until 1945 (then again just before his death from 1952-1954). He was known for the spontaneous power and intensity of his interpretations of the German classics. He expanded the orchestra’s repertoire to include contemporary pieces by Schoenberg, Hindemith, Prokofiev, and Stravinsky and other modern composers, some of whose works he premiered.