It is conjectured that he came up to London in 1593, and became acquainted with Watson, Drayton, and perhaps with Edmund Spenser. The death of Sir Philip Sidney had occurred while Barnfield was still a school-boy, but it seems to have strongly affected his imagination and to have inspired some of his earliest verses. In November 1594, in his twenty-first year, Barnfield published anonymously his first work, The Affectionate Shepherd, dedicated with familiar devotion to Penelope, Lady Rich. This was a sort of florid romance, in two books of six-line stanzas, in the manner of Lodge and Shakespeare, dealing at large with the complaint of Daphnis for the love of Ganymede. As the author expressly admitted later, it was an expansion or paraphrase of Virgils second eclogue Formosum pastor Corydon ardebat Alexin.
Although the poem was successful, it did not pass without censure from the moral point of view. Two months later, in January 1595, Barnfield published his second volume, Cynthia, with certain Sonnets, and this time signed the preface, which was dedicated, in terms which imply close personal relations, to William Stanley, 6th Earl of Derby. This is a book of extreme interest; it exemplifies the earliest study both of Spenser and Shakespeare. Cynthia itself, a panegyric on Queen Elizabeth, is written in the Spenserian stanza, of which it is probably the earliest example extant outside The Faerie Queene.
In 1598 Barnfield published his third volume, The Encomion of Lady Pecunia, a poem in praise of money, followed by a sort of continuation, in the same six-line stanza, called The Complaint of Poetry for the Death of Liberality. In this volume there is already a decline in poetic quality. But an appendix of Poems in diverse Humours to this volume of 1598 presents some very interesting features. Here appears what seems to be the absolutely earliest praise of Shakespeare in a piece entitled A Remembrance of some English Poets, in which the still unrecognized author of Venus and Adonis is celebrated by the side of Spenser, Daniel and Drayton. Here also are the sonnet, If Music and sweet Poetry agree, and the beautiful ode beginning As it fell upon a day, which were once attributed to Shakespeare himself.
In the next year, 1599, The Passionate Pilgrim was published, with the words "By W. Shakespeare" on the title-page. It was long supposed that this attribution was correct, but Barnfield claimed one of the two pieces just mentioned, not only in 1598, but again in 1605. It is certain that both are his, and possibly other things in The Passionate Pilgrim also; Shakespeare's share in the twenty poems of that miscellany being doubtless confined to the five short pieces which have been definitely identified as his.
In all probability Barnfield now married and withdrew to his estate of Dorlestone (or Darlaston), in the county of Stafford, a house romantically situated on the river Trent, where he henceforth resided as a country gentleman. In 1605 he reprinted his Lady Pecunia, and this was his latest appearance as a man of letters. His son Robert Barnfield and his cousin Elinor Skrymsher were his executors when his will was proved at Lichfield; his wife, therefore, doubtless predeceased him. Barnfield died at Dorlestone Hall, and was buried in the neighbouring parish church of St Michaels, Stone, on the March 6, 1627.