Immediately on his return to London Keats's life took a decisive turn as he was caught up in the excitement of powerful new literary friendships. By the middle of October he had been introduced by Cowden Clarke to his hero Leigh Hunt, after Clarke had showed Hunt some of his work. He expressed warm admiration, as did others such as Horace Smith, and a period of close intimacy with the Hunt circle began, matched by a newly dominant stylistic influence from Hunt in Keats's writing. Through Hunt Keats met the painter Benjamin Robert Haydon, already long launched on his picture Christ 's Entry into Jerusalem and in the midst of public controversy over the authenticity of the Elgin Marbles. Keats was attracted to Haydon's artistic commitment and appetite for experience and argument, and Haydon, like many others at this time, was captivated by Keats's genial gusto and contagious sense of humour, and impressed by his passionate sense of poetic vocation. Another new friend, encountered through Haydon on 20 October, was John Hamilton Reynolds, a young writer with a promise that appeared to match Keats's own, and an easy-going quickness of wit that suited Keats's penchant for punning talk and artistic debate. The ‘mad ambition’ of Keats's epistle to his brother George appeared now less emptily fanciful, as the sense of a congenial literary community and audience began to gather substance.

The new intensity in Keats's literary life produced a burst of creativity. One evening in October Clarke introduced Keats to Chapman's translation of Homer, and after returning late to his lodgings he wrote the sonnet ‘On First Looking into Chapman's Homer’, which he contrived to have delivered to Clarke by 10 o'clock next morning. The astonishing achievement of this sonnet, with its confident formal assurance and metaphoric complexity, has already been discussed in the first chapter. As Hunt generously acknowledged, it ‘completely announced the new poet taking possession’.

Through November and December Keats's writing developed rapidly. He took on more directly the myth of his own personal and artistic growth, particularly in two long and ambitious poems, ‘I stood tip-toe upon a little hill ’ and ‘Sleep and Poetry’.