Like many public schoolboys with literary ambitions, Rupert Brooke's poetic mentors shifted over time in response to his passions and tastes. As an adolescent, Brooke preferred the Victorians, particularly Browning. At 18, the list included Rossetti, Swinburne, Dowson, and Wilde. At Cambridge, his interests ran to the Elizabethans, and Geoffrey Keynes, who had been a student at Rugby with Brooke, recalled the fashionable and somewhat affected young poet being given a volume of Baudelaire in 1906.

Keynes, who served in the Royal Army Medical Corps during the war, developing a portable blood transfusion device, later became a great champion of Brooke's. He felt that by the end of Brooke's university years, a combination of awakened political awareness and the maturation of his emotional life meant that the ephemeral literary influences faded. From one who ‘affected to think Tennyson old-fashioned’ and whose ‘enthusiasms were the natural tastes of his age’ emerged a poet of ‘genuine feeling’, so that in the end his later poems were ‘inspired by his own experiences, though few of his friends knew of the heights and the depths of the emotional crisis through which he passed’.

This emphasis on authenticity, on reaction and observation free from affectation or false influence would become a point of praise, as well as a bone of contention, for many readers of Brooke's poetry – and in particular the sequence of poems collected as the War Sonnets – from 1915 onwards. For many readers, these verses, and especially ‘The Soldier’, ‘The Dead’, and ‘Peace’, in descending order of popularity, rang with the authenticity of the enthusiastic volunteer demonstrating the purest patriotism. They represented an update of the work of canonical poets like Byron, Tennyson, and Kipling, speaking to, and for, a new generation. Brooke and his poems were an affirmation of the ‘English’ values of honour, aestheticised youth and friendship and, ultimately, self-sacrifice. They were also a product of Brooke's personal experience of the war, as well as what he perceived to be general ‘undercurrent[s] of feeling’, captured and fixed in verse, through which he strove towards Coleridge's ideal of the ‘great poet’.