Gonne met Yeats in 1889, when she was 24. He asked her to marry him regularly, even as she had children with another man. She then married someone else. When that union ended in 1908, Yeats comforted her. In 1916, he once again asked the then 50-year-old Maud to marry him. She declined, but gave him permission to propose to her 22-year-old daughter, who also refused the offer. Within a year, he'd married the woman who, when he died in 1939, was at his bedside, along with his last lover. As I've said before: Poets! They're just like us!
I have written poems to lovers and had them written to me, but none as elegiacally sweet and sour as Yeats' When You are Old:
When you are old and gray and full of sleep
And nodding by the fire, take down this book,
And slowly read, and dream of the soft look
Your eyes had once, and of their shadows deep;
How many loved your moments of glad grace,
And loved your beauty with love false or true;
But one man loved the pilgrim soul in you,
And loved the sorrows of your changing face.
And bending down beside the glowing bars,
Murmur, a little sadly, how love fled
And paced upon the mountains overhead,
And hid his face amid a crowd of stars.
(Photo of Gonne found at the amusing Irish blog The Chancer.)