Modernist poetry refers to poetry written between 1890 and 1950 in the tradition of modernist literature in the English language, but the dates of the term depend upon a number of factors, including the nation of origin, the particular school in question, and the biases of the critic setting the dates. It is usually said to have begun with the French Symbolist movement and it artificially ends with the Second World War. The beginning and ending of the modernist period are of course arbitrary: poets like Yeats and Rilke started in a post-Romantic, Symbolist vein and modernised their poetic idiom under the impact of political and literary developments; other poets, like T.S. Eliot, Ezra Pound, or E.E. Cummings went on to produce significant work after World War II.
The questions of impersonality and objectivity seem to be crucial to Modernist poetry. Modernism developed out of a tradition of lyrical expression, emphasising the personal imagination, culture, emotions and memories of the poet. For the modernists, it was essential to move away from the merely personal towards an intellectual statement that poetry could make about the world. Even when they reverted to the personal, like Eliot in the Four Quartets or Pound in the The Cantos, they distilled the personal into a poetic texture that claimed universal human significance.
After World War II, a new generation of poets sought to revoke the effort of their predecessors towards impersonality and objectivity. Modernism ends with the turn towards confessional poetry in the work of Robert Lowell and Sylvia Plath, among others.