The demands of his twin appointments in Vienna initially absorbed all Mahler's time and energy, but by 1899 he had resumed composing. The remaining Vienna years were to prove particularly fruitful. While working on the last of his Des Knaben Wunderhorn settings he started his Fourth Symphony, which he completed in 1900. By this time he had abandoned the composing hut at Steinbach and had acquired another, at Maiernigg on the shores of the Wörthersee in Carinthia, where he later built a villa.
In this new venue Mahler embarked upon what is generally considered as his "middle" or post-Wunderhorn compositional period. Between 1901 and 1904 he wrote ten settings of poems by Friedrich Rückert, five of which were collected as Rückert-Lieder. The other five formed the song cycle Kindertotenlieder ("Songs on the Death of Children"). The trilogy of orchestral symphonies, the Fifth, the Sixth and the Seventh were composed at Maiernigg between 1901 and 1905, and the Eighth Symphony written there in 1906, in eight weeks of furious activity.