Sexual Symbolism
Although it may not seem like it to readers unfamiliar with symbolic language, the poem is actually quite explicit in its description of a sexual assault. Because it is not intended to be pornographic or literal in any other senses, figurative language is adopted as substitutions for coarser language that would be more readily understandable. The reference to “tower” should be a familiar enough phallic symbol that it is probably the least likely to miss interpretation. The “broken wall” and the “burning roof” may be somewhat less obvious as metaphorical language for the vagina.
Swan
The bird described in the narrative is never actually identified as a swan. To fully grasp this poem, it is of tremendous help to be acquainted with some knowledge of ancient Greek mythology. Into that mythology was written the story of the conception of the woman who would become known as Helen of Troy. Unless one is familiar with the story of Zeus transforming into a swan to rape Leda, Helen’s mother, it would likely be not just impossible to determine that the swan is a symbol of Zeus but that the bird is even a swan. It gets even more complicated: swans are a favorite animal for Yeats to work into his verse as a symbol of inscrutable passion and desire.
Ireland
Leda exists more literally than Zeus by virtue of being named though she would still be a mystery to anyone not aware of her rape by Zeus. Another far more nebulous symbolic level, however, Leda is also a metaphor for Ireland under the yoke of British oppression. In this sense, the swan’s standing takes Zeus out of mythology and applies him more specifically as a corrupt god using his power to invade a dominion not his own—mortals—and physical rape of a woman is elevated to the sphere of political rape of one culture by a more powerful culture.
The Annunciation
All new epochs in history begin, for Yeats, with a violation; the rape of Leda heralds the beginning of a 2,000 year cycle of history called the Classical Age which will, in turn, end with another violation of a mortal female by a god. Yeats appropriates the symbolism here from Christian dogma; when Mary is informed by the archangel that she carries the son of God, it is known as the Annunciation. Yeats works backward apply it here as the annunciation of the essential event which will give rise to the Trojan War which brings the previous cycle to an end. The rape itself is therefore a symbol of epochal change in civilization.
Agamemnon Dead
The abrupt, stark reference to Agamemnon—the Greek commander during the Trojan War—being dead makes identifies him as the symbol of the death of the Greek civilization which is laid to rest as a result of the Trojan War. Helen is the figure which launches that long conflict and as the offspring of the rape of her mother Leda by Zeus, she is the symbolic incarnation of the movement forward from that cycle.
