Imagism flourished in Britain and in the United States for a brief period that is generally considered to be somewhere between 1909 and 1917. As part of the modernist movement, away from the sentimentality and moralizing tone of nineteenth-century Victorian poetry, imagist poets looked to many sources to help them create a new poetic expression.

For contemporary influences, the imagists studied the French symbolists, who were experimenting with free verse (vers libre), a verse form that used a cadence that mimicked natural speech rather than the accustomed rhythm of metrical feet, or lines. Rules of rhyming were also considered nonessential. The ancient form of Japanese haiku poetry influenced the imagists to focus on one simple image. Greek and Roman classical poetry inspired some of the imagists to strive for a high quality of writing that would endure. 

T. E. Hulme is credited with creating the philosophy that would give birth to the Imagism movement. Although he wrote very little, his ideas inspired Ezra Pound to organize the new movement. Pound's "In a Station of the Metro" is often given as one of the purest of his imagist poems. Amy Lowell took over the leadership role of the imagists when Pound moved on to other modernist modes. Her most anthologized poems include "Lilacs" and "Patterns."

Other important imagist poets include Hilda Doolittle, whose poem "Sea Poppies" reflects the Japanese influence on her writing, and her "Oread" is often referred to as the most perfect imagist poem; Richard Aldington, who was one of the first poets to be recognized as an imagist, and whose collection Images of War is considered to contain some of the most intense depictions of World War I; F. S. Flint, who dedicated his last collection of imagist poems, Otherworld: Cadences to Aldington; and John Gould Fletcher, whose collection Goblins and Pagodas is his most representative work under the influence of Imagism.