The artist John Linnell visited Blake in June 1818 and hired him to etch the preliminary stages of a portrait of James Upton. From this modest beginning developed a relationship that shaped the final nine years of Blake's life. Although Linnell was thirty-five years Blake's junior, they became good friends, attending art exhibitions and the theatre together. After Linnell moved to Hampstead in March 1824, Blake, always a great walker, often made the uphill journey on foot. There he ‘sang, in a voice tremulous with age, sometimes old ballads, sometimes his own songs, to [unrecorded] melodies of his own’ (Gilchrist, 1.294).


The artist John Varley was among the first in a new circle of friends to which Linnell introduced Blake. During séance-like sessions, beginning in October 1819 and intermittently repeated during the next six years, Blake drew for Varley over one hundred ‘Visionary Heads’ of persons historical (Edward I, William Wallace) and spiritual (The Man who Taught Blake Painting in his Dreams). Varley, prompted by his interests in physiognomy and astrology, apparently believed in the literal presence of these figures. Blake may have taken the conjurations less seriously, yet his belief in the reality of imaginative apperception is consistent with visionary portraiture. Blake developed one of his more bizarre images, The Ghost of a Flea, into a tempera painting; Linnell's engravings of the creature's anthropomorphic head were published in Varley's Treatise on Zodiacal Physiognomy (1828).


In September 1819 Linnell introduced Blake to his family physician, Robert Thornton, who soon after hired Blake to design illustrations for Ambrose Philips's ‘Imitation’ of Virgil's first eclogue to appear in the third edition of Thornton's school text of Virgil. Blake first produced a relief etching of four small vignettes. These were rejected, probably for reasons both technical and stylistic. As with the Grave project years earlier, Blake had failed to introduce one of his special graphic methods into a commercial publication. He next prepared twenty-one wash drawings—apparently accepted by Thornton and his publishers—and executed seventeen as wood-engravings. These were so ruggedly different from established conventions that they would have been excluded from Thornton's 1821 edition except for praise from several respected artists, including Sir Thomas Lawrence. The images of melancholy and disruption pictured in Blake's only engravings in wood suggest that Virgil's pastoral lament reminded Blake of his own pastoral sojourn in Felpham under Hayley's burdensome patronage.

Blake's financial circumstances had not improved by the early 1820s; indeed, he may have become poorer. In 1821 he sold his collection of old master prints and moved to just two rooms at 3 Fountain Court, Strand. Blake received a charitable grant of £25 from the Royal Academy in June 1822; Thomas Lawrence also assisted with a gift of money. Blake persevered through these trying times, painting in 1821 one of his most mysterious allegorical designs, The Sea of Time and Space, illustrating Milton's Paradise Regained with twelve watercolours, and in 1822 etching in relief two brief works, On Homers Poetry [and] On Virgil, a disquisition on the errors of classicism, and The Ghost of Abel, a response to Byron's Cain: a Mystery. In the latter, Blake emphasizes the need for forgiveness, suggesting that Blake was seeking release from self-defeating anger through the forgiveness of erstwhile enemies.


Linnell's commissions may have been motivated in part by a desire to provide the ageing artist with a regular income. Blake had produced for Butts a series of nineteen watercolour illustrations to the book of Job in 1805–6. Linnell traced these in September 1821; Blake later coloured the tracings and added two more designs. This work provided the basis for the contract, signed by Linnell and Blake on 25 March 1823, to engrave the Job illustrations. The commission provided Blake an income of about £1 a week from 1823 through 1825. The task proved arduous, for Blake engraved the plates without preliminary etching, and the twenty-one designs plus an engraved title-page were not published until March 1825. Blake's graphic retelling of the story begins with Job's blind adherence to the letter of the law; follows Job and his wife through miseries inflicted by Satan, a projection of Job's false vision; and concludes with Job restored to prosperity, the physical sign of his spiritual awakening. Blake's mastery of traditional line engraving in the Job illustrations recalls the Renaissance artists he so much admired, particularly Dürer; but the interplay between darkness and light exhibited throughout the series may have been influenced by Linnell's engraving style. This revival of traditional graphics prompted Blake, probably at some point after 1818, to return to intaglio plates he had executed years earlier, including Joseph of Arimathea and the large Job and Ezekiel separate plates, thoroughly to revise them and add new inscriptions. The emblems For Children became For the Sexes: the Gates of Paradise.

Through Linnell, a group of young artists met Blake and came to admire him greatly, both for his character and his art. They looked upon him as a seer or Old Testament prophet come to life; in turn, Blake's peace of mind was enhanced by finding a worshipful audience. Samuel Palmer, only nineteen when first recorded in Blake's company in May 1824, would kiss the ‘bell-handle’ before entering Blake's home, which the group called ‘the House of the Interpreter’ after a passage in Bunyan's Pilgrim's Progress illustrated by one of Blake's white-line etchings (Bentley, Records, 292, 295). George Richmond was the most influenced by the figural style of Blake's art. Works by Palmer and Edward Calvert reveal their profound debt to the Virgil wood-engravings, described by Palmer as ‘visions of … Paradise; models of the exquisitest pitch of intense poetry’ (ibid., 271). This loose brotherhood of Blake followers, one that also included Francis Oliver Finch, Frederick Tatham, and Welby Sherman, called themselves ‘The Ancients’ and often sought their own intense responses to nature in the environs of Shoreham, Kent, which Blake visited in late summer 1825.

Blake's youthful associations, perhaps rich with memories of the lost bond with his brother Robert, were complemented by gatherings at the home of Linnell's patrons Charles and Elizabeth Aders. There Blake met Henry Crabb Robinson, who had written an article about Blake in 1811 for a German periodical and had discussed Blake's poems with William Wordsworth and Samuel Taylor Coleridge. Late in 1825, Robinson began to record Blake's conversations, including gnomic observations uttered in all honesty, but in such a way as to perplex the audience. Robinson writes in his Reminiscences that Blake said:
     the most strange things in the most unemphatic manner, speaking        of his visions as any man would of the most ordinary occurances. ‘…      I was Socrates’—and then as if he had gone too far in that—‘Or a         sort of brother—I must have had conversations with him—So I had with Jesus Christ.’ … Concerning the imputed Divinity of Jesus Christ He answered—‘he is the only God’—but then he added—‘and so am I and so are you’. (Robinson in Bentley, Records, 538–40)

As in The Marriage of Heaven and Hell and the ‘Visionary Heads’, Blake again intertwined the profound and the playful.

Continued creativity, in spite of declining health, characterizes Blake's final years. He executed a separate etching/engraving of the Laocoön c.1826, surrounding the famous Hellenistic sculpture with aphorisms on the unity of art and religion and the evils of money and empire. New customers for the Songs of Innocence and of Experience led Blake to print and elaborately hand colour five copies in the last three years of his life. In the summer of 1824, long before the Job engravings were completed, Linnell commissioned an even larger project, the illustration of Dante's Divine Comedy, which provided Blake an income of about £2 a week. He ‘applied himself to learning Italian’ (Gilchrist, 1.334) and produced 102 watercolours which, like the seven Dante engravings, remained incomplete at his death. Other endeavours cut short by mortality included twenty-nine watercolour illustrations to Bunyan's Pilgrim's Progress, begun in 1824, and an illuminated manuscript of Genesis.