William Butler Yeats's relationship with the beautiful and defiant Irishwoman Maud Gonne is one of the great literary love stories of the 20th century. He was a buttoned-up poet with conservative tendencies; she was a free-spirited actress who wanted nothing less than revolution for her country. Maybe he should have known better, but hey, that's love.

Yeats published "No Second Troy" in 1916 in the collection Responsibilities and Other Poems, after he had already proposed to Gonne – and been rejected – on numerous occasions. (Hey, you gotta admire his persistence.) Having pursued her for over a decade and dedicated many of his poems to her, we think it's fair to say that Yeats was obsessed with her.

In this poem, however, Yeats's attitude is somewhat harsh, as he compares Gonne with the infamously beautiful – and notoriously mischievous – Helen of Troy. Helen is a legendary character from Homer's Iliad. Like Maud Gonne, Helen was considered one of the most beautiful women of her age. She was also partly responsible for starting the Trojan War, which eventually led to the burning of the great city of Troy. Many legends paint her as a romantic who left her husband Menelaus for the beautiful but cowardly Trojan Prince Paris. Angry husband + massive armies = Trojan War.

With the comparison to Helen, Yeats is accusing Maud Gonne of being partially responsible for the violence in revolutionary Ireland, just like Helen was partially responsible for the Trojan War. According to "No Second Troy," she "taught to ignorant men most violent ways."

Gonne had always been more of a firebrand than Yeats, and she endorsed the more radical and violent revolutionary efforts to secure Ireland's independence from Britain in the first decades of the 20th century. In 1916, her husband, John MacBride, took part in the violent Easter Rising against the British. In the wake of the uprising, MacBride and many others were executed. Yeats did not believe in violent rebellion, and afterward he wrote one of his most famous and painful poems, "Easter 1916," in which he declared, "A terrible beauty is born."

OK, enough history. All this is merely to say that Gonne was a combustible presence in Yeats's life, and his conflicted emotions about her spill out into this brilliant poem. It's a hot mess, all right, but in his characteristic way, Yeats manages to squeeze all his passion into a short, controlled space. A terrible beauty, indeed.

Nobody likes a simple love story. Two people meet, fall in love, get married...yadda yadda yadda. Booooring. We need a bit more complication. More drama. Besides, many love affairs don't have a happy ending.

W.B. Yeats's love for Maud Gonne is one such story of unrequited love. The story is fascinating enough on its own (at one point Yeats even proposed to Gonne's daughter and was rejected!), but when you throw revolutionary politics into the mix, it's a downright barnburner. Love and politics is always an irresistible combination, whether it's Helen and Paris, Antony and Cleopatra, Romeo and Juliet, or Rick and Ilsa from Casablanca.

"No Second Troy" expresses that moment in a tortured love affair when the unrequited lover, fed up with all the games and shenanigans that have been simmering beneath the surface, finally unloads all his emotions in a fit of brutal honesty. You want to know what I really think of you? Get ready ...You can't help but watch with bated breath.

What Yeats really thinks of Gonne – at least around 1916, when he wrote this poem – is that she is a courageous and devastatingly beautiful woman. She's also a cruel lover and a shamelessly irresponsible activist. She uses her beauty and her high ideals to convince people less noble and intelligent to do what he considers some very unwise things, like oppose the might of the British colonial powers. Yeats's love for Gonne and his love for his country collide in dramatic fashion, pulling him this way and that. In the end, his love of Ireland and nonviolence win the day, and he comes close to condemning Gonne through the damning comparison to Helen of Troy.

Although the struggle for independence in Ireland may be over, we suspect love stories like the one that animates this poem will continue to play out in the context of political conflicts all over the globe. Come for the history lesson, stay for the bitter reproaches of tormented love.