Answer by taking a quote from the following article:

Richard Georg Strauss (11 June 1864 - 8 September 1949) was a leading German composer of the late Romantic and early modern eras. He is known for his operas, which include Der Rosenkavalier, Elektra, Die Frau ohne Schatten and Salome; his Lieder, especially his Four Last Songs; his tone poems, including Don Juan, Death and Transfiguration, Till Eulenspiegel's Merry Pranks, Also sprach Zarathustra, Ein Heldenleben, Symphonia Domestica, and An Alpine Symphony; and other instrumental works such as Metamorphosen and his Oboe Concerto. Strauss was also a prominent conductor in Western Europe and the Americas, enjoying quasi-celebrity status as his compositions became standards of orchestral and operatic repertoire.

Strauss wrote two early symphonies: Symphony No. 1 (1880) and Symphony No. 2 (1884). However, Strauss's style began to truly develop and change when, in 1885, he met Alexander Ritter, a noted composer and violinist, and the husband of one of Richard Wagner's nieces. It was Ritter who persuaded Strauss to abandon the conservative style of his youth and begin writing tone poems. He also introduced Strauss to the essays of Wagner and the writings of Arthur Schopenhauer. Strauss went on to conduct one of Ritter's operas, and at Strauss's request Ritter later wrote a poem describing the events depicted in Strauss's tone poem Death and Transfiguration.  The new influences from Ritter resulted in what is widely regarded as Strauss's first piece to show his mature personality, the tone poem Don Juan (1888), which displays a new kind of virtuosity in its bravura orchestral manner. Strauss went on to write a series of increasingly ambitious tone poems: Death and Transfiguration (1889), Till Eulenspiegel's Merry Pranks (1895), Thus Spoke Zarathustra (1896), Don Quixote (1897), Ein Heldenleben (1898), Symphonia Domestica (1903) and An Alpine Symphony (1911-1915). One commentator has observed of these works that "no orchestra could exist without his tone poems, written to celebrate the glories of the post-Wagnerian symphony orchestra."  James Hepokoski notes a shift in Strauss's technique in the tone poems, occurring between 1892 and 1893. It was after this point that Strauss rejected the philosophy of Schopenhauer and began more forcefully critiquing the institution of the symphony and the symphonic poem, thereby differentiating the second cycle of tone poems from the first.

What was one of his orchestral works?
Strauss wrote two early symphonies: Symphony No. 1 (1880) and Symphony No. 2 (1884).