Going back to the original question, a few important notes for reference.

Yeats was born in Sandymount, Dublin, and was part of an Anglo-Irish family with deep roots on his mother's side in Sligo. His father, who was a bit of a ne'er-do-well, wandered back and forth between London and Dublin and Sligo, and Yeats eventually fetched up in London in the 1890s. His first poems were very influenced by Shelley, and he became caught up in the end of the 19th century esoteric movements (he wrote on Blake, for example), and belonged to various esoteric orders that show up in his early stories, like The Tables of The Law, Rosa Alchemica, and so on. In the mid-1890s he got involved in the Irish movement, which he helped push at the cultural level, along with Lady Gregory, later J.M. Synge, and others. The great moment of his life, of course, was meeting Maud Gonne, who was a beautiful revolutionary and somewhat erratic, to say the least. Yeats was passionately in love with her for years -- it has only recently been revealed that they did, at very long last, sleep together. He even went so far later in life as to proposition her daughter, Iseult.

Somewhere around 1914, if I recall, thanks in part to the influence of Ezra Pound, Yeats started writing a sparser, harder poetry, which has always been my personal favourite. He eventually married an old friend, Dorothy Shakespeare, who turned out to be a whiz at ghost writing; and somehow Yeats connected this to his evolving esoteric writings which were a mixture of Nietszche and Oscar Wilde, having to do with the need for the poet to create a persona (a mask) which would be truer than the ordinary self; and each era of history is in part exemplified by the masks worn by its representative heros. The later symbolism links this to the phases of the moon, and a whole range of cyclical interpenetrations. I studied it all in detail at one time, and I think you don't really need much more than what I said above to get the feel for his later stuff.

In the 1920's and later he became famous, Nobel prize winner, and so on. His Irish home, Thoor Ballylee (the Tower of many poems) is a national monument near Gort in the West of Ireland, and is worth a long detour to see, and walk around.

Jeffaries edition of the poems is the standard, though now that Yeats is out of copyright, there are competing ones. Macmillan owned them all, and their editions of the plays and essays are mostly Yeats' own. I have met a few people who like his plays -- I have acted in a couple: they are sort of like Irish kabuki plays. Never did anything for me.

His essays are almost all fabulous, though no one reads them much. His Autobiography and Memoirs are stunningly beautiful prose, some of the best ever written in English. His short stories are not very interesting.

As mentioned, Richard Ellmann's work on Yeats is the best: anything is good -- The Man and the Masks especially. Ellmann had the good fortune to be befriended by Mrs. Yeats, and got a lot of good stuff early on.

Many years ago I had the honour of working for a time as a helper on an edition of some of Yeats' stories, so I have a soft spot in my heart for him (though not for the stories). His brother Jack is probably the best known modern Irish artist.

yours, Peter T.