Edward Thomas was born in London in 1878 and was educated at St Paul's School and Lincoln College Oxford. He published his first book, a collection of essays on the country, in 1896, with the encouragement of the critic James Ashcroft Noble. In 1899, while he was still an undergraduate, Thomas married Helen Noble (1877-1967), the daughter of his mentor. Their son Mervyn was born in 1900 and their elder daughter Bronwen in 1903. Myfanwy Thomas, their third child, was born in 1910.

The family moved house frequently, but from 1906 lived in or near Petersfield, Hampshire, an area whose landscape was to have a strong influence on Thomas's poetry. Thomas sought to make a living as a writer, reviewing and publishing essays, anthologies, biographies, guidebooks and country writing. In 1913 his autobiographical novel The Happy-go-lucky Morgans was published. He also began to write poetry, but the strain of reconciling his own creativity with the need to earn enough to support his family created periods of deep depression during these years.

In 1913 Thomas met Robert Frost, a friendship that was of profound importance to his own poetry. In 1915 Thomas enlisted in the Artists' Rifles, transferring a year later to the Royal Artillery, where he trained as a map-reading instructor and was commissioned second lieutenant. He volunteered for service overseas and was posted to France in January 1917. On 9 April Thomas was killed at the battle of Arras.

His poetry was published posthumously: Poems (1917) under his pseudonym, Edward Eastaway, Last Poems in 1918 and his Collected Poems in 1920. Helen Thomas's accounts of her life with Thomas in As it Was (1926) and World without End (1931) were published with Myfanwy Thomas's memoir of her childhood as Under Storm's Wing (Carcanet Press, 1988).