When did western imagist poetry come into being?

The appearance of imagism was originally a reversal of the poetic style at that time. First of all, symbolism, aestheticism and romanticism merged with each other in the English literary world in the late19th century, forming a new romanticism. Imagism evolved on its basis, and Bergson became it. By the beginning of the 20th century, traditional poetry, especially romanticism and Victorian poetry, had degenerated into moaning, sentimentality and ethical preaching, and was only "an imitation of Keats and Wordsworth". Pound and his Imagist put forward the idea of "being unconventional" and "being innovative". Secondly, Bergson fever was popular in the early 20th century, which is an extension of the influence of irrational philosophy in the literary world since Schopenhauer. Hume, the pioneer of Imagism, was directly taught by Bergson. Bergson's intuitionism and philosophy of life are accepted by imagists and become their main theoretical and philosophical basis. Imagist poetry especially emphasizes the role of images and intuition. At the same time, the symbolism poetry school created a new way for Imagist to create new poems, especially the synaesthesia, color and musicality of poems, which greatly inspired Imagist.