Sailing to Byzantium

Summary
The speaker, referring to the country that he has left, says that it is "no country for old men": it is full of youth and life, with the young lying in one another's arms, birds singing in the trees, and fish swimming in the waters. There, "all summer long" the world rings with the "sensual music" that makes the young neglect the old, whom the speaker describes as "Monuments of unageing intellect."
An old man, the speaker says, is a "paltry thing," merely a tattered coat upon a stick, unless his soul can clap its hands and sing; and the only way for the soul to learn how to sing is to study "monuments of its own magnificence." Therefore, the speaker has "sailed the seas and come / To the holy city of Byzantium." The speaker addresses the sages "standing in God's holy fire / As in the gold mosaic of a wall," and asks them to be his soul's "singing-masters." He hopes they will consume his heart away, for his heart "knows not what it is"--it is "sick with desire / And fastened to a dying animal," and the speaker wishes to be gathered "Into the artifice of eternity."
The speaker says that once he has been taken out of the natural world, he will no longer take his "bodily form" from any "natural thing," but rather will fashion himself as a singing bird made of hammered gold, such as Grecian goldsmiths make "To keep a drowsy Emperor awake," or set upon a tree of gold "to sing / To lords and ladies of Byzantium / Or what is past, or passing, or to come."
Form
The four eight-line stanzas of "Sailing to Byzantium" take a very old verse form: they are metered in iambic pentameter, and rhymed ABABABCC, two trios of alternating rhyme followed by a couplet.
Commentary
"Sailing to Byzantium" is one of Yeats's most inspired works, and one of the greatest poems of the twentieth century. Written in 1926 and included in Yeats's greatest single collection, 1928's The Tower, "Sailing to Byzantium" is Yeats's definitive statement about the agony of old age and the imaginative and spiritual work required to remain a vital individual even when the heart is "fastened to a dying animal" (the body). Yeats's solution is to leave the country of the young and travel to Byzantium, where the sages in the city's famous gold mosaics (completed mainly during the sixth and seventh centuries) could become the "singing-masters" of his soul. He hopes the sages will appear in fire and take him away from his body into an existence outside time, where, like a great work of art, he could exist in "the artifice of eternity." In the astonishing final stanza of the poem, he declares that once he is out of his body he will never again appear in the form of a natural thing; rather, he will become a golden bird, sitting on a golden tree, singing of the past ("what is past"), the present (that which is "passing"), and the future (that which is "to come").
A fascination with the artificial as superior to the natural is one of Yeats's most prevalent themes. In a much earlier poem, 1899's "The Lover Tells of the Rose in His Heart," the speaker expresses a longing to re-make the world "in a casket of gold" and thereby eliminate its ugliness and imperfection. Later, in 1914's "The Dolls," the speaker writes of a group of dolls on a shelf, disgusted by the sight of a human baby. In each case, the artificial (the golden casket, the beautiful doll, the golden bird) is seen as perfect and unchanging, while the natural (the world, the human baby, the speaker's body) is prone to ugliness and decay. What is more, the speaker sees deep spiritual truth (rather than simply aesthetic escape) in his assumption of artificiality; he wishes his soul to learn to sing, and transforming into a golden bird is the way to make it capable of doing so.
"Sailing to Byzantium" is an endlessly interpretable poem, and suggests endlessly fascinating comparisons with other important poems--poems of travel, poems of age, poems of nature, poems featuring birds as symbols. (One of the most interesting is surely Keats's "Ode to a Nightingale," to which this poem is in many ways a rebuttal: Keats writes of his nightingale, "Thou wast not born for death, immortal Bird! / No hungry generations tread thee down"; Yeats, in the first stanza of "Sailing to Byzantium," refers to "birds in the trees" as "those dying generations.") It is important to note that the poem is not autobiographical; Yeats did not travel to Byzantium (which was renamed Constantinople in the fourth century A.D., and later renamed Istanbul), but he did argue that, in the sixth century, it offered the ideal environment for the artist. The poem is about an imaginative journey, not an actual one.
Context
William Butler Yeats was born in Dublin in 1865 to a chaotic, artistic family. His father, a portrait painter, moved the family to London when Yeats was two, and William spent much of his childhood moving between the cold urban landscape of the metropolis and the congenial countryside of County Sligo, Ireland, where his mother's parents lived. An aesthete even as a boy, Yeats began writing verse early, and published his first work in 1885. In 1889, Yeats met the Irish patriot, revolutionary, and beauty Maud Gonne. He fell immediately in love with her, and remained so for the rest of his life; virtually every reference to a beloved in Yeats's poetry can be understood as a reference to Maud Gonne. Tragically, Gonne did not return his love, and though they remained closely associated (she portrayed the lead role in several of his plays), they were never romantically involved. Many years later, Yeats proposed to her daughter--and was rejected again.
Yeats lived during a tumultuous time in Ireland, during the political rise and fall of Charles Stuart Parnell, the Irish Revival, and the civil war. Partly because of his love for the politically active Maud Gonne, Yeats devoted himself during the early part of his career to the Literary Revival and to Irish patriotism, seeking to develop a new religious iconography based on Irish mythology. (Though he was of Protestant parentage, Yeats played little part in the conflict between Catholics and Protestants that tore Ireland apart during his lifetime.) He quickly rose to literary prominence, and helped to found what became the Abbey Theatre, one of the most important cultural institutions in Ireland, at which he worked with such luminaries as Augusta Gregory and the playwright John Synge. In 1923, Yeats was awarded the Nobel Prize for Literature.
One of the most remarkable facts about Yeats's career as a poet is that he only reached his full powers late in life, between the ages of 50 and 75. Indeed, after reaching his height, he sustained it up until the very end, writing magnificent poems up until two weeks before his death. The normal expectation is that a poet's powers will fade after forty or fifty; Yeats defied that expectation and trumped it entirely, writing most of his greatest poems--from the crushing power of The Tower to the eerie mysticism of the Last Poems--in the years after he won the Nobel Prize, a testament to the force and commitment with which he devoted himself to transforming his inner life into poetry. Because his work straddles the nineteenth and twentieth centuries, Yeats is stylistically quite a unique poet; his early work seems curiously modern for the nineteenth century, and his late work often seems curiously un-modern for the 1930s. But Yeats wrote great poems in every decade of his life, and his influence has towered over the past six decades; today, he is generally regarded as the greatest poet of the twentieth century.
Analysis
Yeats is the greatest poet in the history of Ireland and probably the greatest poet to write in English during the twentieth century; his themes, images, symbols, metaphors, and poetic sensibilities encompass the breadth of his personal experience, as well as his nation's experience during one of its most troubled times. Yeats's great poetic project was to reify his own life--his thoughts, feelings, speculations, conclusions, dreams--into poetry: to render all of himself into art, but not in a merely confessional or autobiographical manner; he was not interested in the common-place. (The poet, Yeats famously remarked, is not the man who sits down to breakfast in the morning.) His elaborate iconography takes elements from Irish mythology, Greek mythology, nineteenth-century occultism (which Yeats dabbled in with Madame Blavatsky and the Society of the Golden Dawn), English literature, Byzantine art, European politics, and Christian imagery, all wound together and informed with his own experience and interpretive understanding.
His thematic focus could be sweepingly grand: in the 1920s and '30s he even concocted a mystical theory of the universe, which explained history, imagination, and mythology in light of an occult set of symbols, and which he laid out in his book A Vision (usually considered important today only for the light it sheds on some of his poems). However, in his greatest poems, he mitigates this grandiosity with a focus on his own deep feeling. Yeats's own experience is never far from his poems, even when they seem obscurely imagistic or theoretically abstract, and the veil of obscurity and abstraction is often lifted once one gains an understanding of how the poet's lived experiences relate to the poem in question.
No poet of the twentieth century more persuasively imposed his personal experience onto history by way of his art; and no poet more successfully plumbed the truths contained within his "deep heart's core," even when they threatened to render his poetry clichéd or ridiculous. His integrity and passionate commitment to work according to his own vision protect his poems from all such accusations. To contemporary readers, Yeats can seem baffling; he was opposed to the age of science, progress, democracy, and modernization, and his occultist and mythological answers to those problems can seem horribly anachronistic for a poet who died barely sixty years ago. But Yeats's goal is always to arrive at personal truth; and in that sense, despite his profound individuality, he remains one of the most universal writers ever to have lived.

Detailed explanation of Sailing to Byzantium
Theme: In our obsession with the flesh, we have neglected the mind, and we must constantly strive for that blissful reunion of the aesthetic, the intellectual, and the spiritual.
1st stanza: The poet is an old man who desires to leave "that country." Notice the "procreative" imagery - the mackerel-crowded seas, the salmon-falls, the image of 2 lovers - therefore, "that country" refers to the world of flesh, the material world. He yearns for monuments of unageing intellect, that is, the things of the MIND, rather than the sensual music that is representative again of the material world.
Comments:
1st stanza: The poet is an old man who desires to leave "that country."  Notice the "procreative" imagery - the mackerel-crowded seas, the salmon-falls, the image of 2 lovers - therefore, "that country" refers to the world of flesh, the material world.  He yearns for monuments of unageing intellect, that is, the things of the MIND, rather than the sensual music that is representative again of the material world .
2nd stanza: The poet, it seems, is embarking on a journey of intellect to Byzantium. It is vital that you know of Yeats' perspective on this "holy city:" he believed that Byzantium was a union of the practical, spiritual/religious, and the aesthetic - a golden age or paradise lost that we must always strive to regain.
Comments:
2nd stanza: The poet, it seems, is embarking on a journey of intellect to Byzantium.  It is vital that you know of Yeats' perspective on this "holy city:" he believed that Byzantium was a union of the practical, spiritual/religious, and the aesthetic - a golden age or paradise lost that we must always strive to regain .
3rd stanza: The poet is calling upon the wise teachers, the intellectual minds of the past, the sages, for the strength and will power "be the singing-masters of my soul" to separate himself from the material world. "Perne in a gyre" simply means spinning in a spiral motion.
Comments:
3rd stanza: The poet is calling upon the wise teachers, the intellectual minds of the past, the sages, for the strength and will power "be the singing-masters of my soul" to separate himself from the material world.  "Perne in a gyre" simply means spinning in a spiral motion .
4th stanza: The poet wishes for something of the fantastical in this stanza. Gold here is a symbol of eternity (does not tarnish) and of the beautiful/aesthetic. Here, Yeats recalls a tale he read where artificial birds sang in the Emperor's palace. The "goldsmith" is a mythological allusion to Hephaestus, the god of the forge (I'm not sure of the origin of this myth however).
Comments:
: 4th stanza: The poet wishes for something of the fantastical in this stanza.  Gold here is a symbol of eternity (does not tarnish) and of the beautiful/aesthetic.  Here, Yeats recalls a tale he read where artificial birds sang in the Emperor's palace.  The "goldsmith" is a mythological allusion to Hephaestus, the god of the forge (I'm not sure of the origin of this myth however .