Free Verse originated in the late 19th centaury with French poets such as Arthur Rimbaud and Jules Laforgue. These poets wanted a type of poetry that was free of any conventions so "Vers Libre" was used to describe this change in French Poetry. The purpose of this change was for the French Poets to change the restrictions that poetry had at the time and to re-create the rhythms of natural speech. The Old English and Medieval poetry had some freedom to it. For example the Palms of King James version of the bible. Free Verse became popular in England in the 20th Centaury from the influence that the French poetry had on students who were studying it at the time. Free verse is described to be a form of poetry that is flexible, modern and casual and that it reflects the spirit of the modern age.
There really aren't any conventions of free verse Poetry because free Verse is really a style of poetry that has no limitations. Because free Verse doesn't rely on a rhythmic meter it is replaced by the natural rhythms of ordinary speech. So the rhythm is based on phrases, sentences and paragraphs. The flow of a Free Verse poem is often random and it rises and falls with the poets emotions and thoughts. This makes the poetry lose its artificiality because it isn't written in just one particular way. Although this form of poetry is formless it does however rely on the poet to structure the poem in a way that it works with the meaning and that the poet has to be very creative when writing in free verse. A Free verse poem contains many other poetic devices in absence of rhythm. Many other techniques that are used are alliteration, assonance, metaphors and similes.
Poets that wrote in free verse were T.E. Hulme, Ezra Pound and T.S. Elliot. Other poets that had experimented with free verse were the romantic poets; John Keats Samuel Taylor Coleridge
Percy Bysshe Shelley
and William Wordsworth
Also some American poets wrote in free verse as...