In what way did Yeats' relationship with Maud Gonne influence his poetry?

I think that it is important to view the life of a poet in
a context, but not use it to draw too great of a portrait of the artist in relationship
to their work.  In terms of Yeats' relationship with Gonne, there are some significant
points to raise in light of Yeats' work.  On one hand, there is Gonne's nationalism, and
the face that the love was one sided. Yeats' exploration into mysticism and what might
transcend Western and Irish cultures preluded him from seeing nationalism as the sole
notion of the good.  This was not the case with Gonne, who had little problem in placing
all her proverbial intellectual marbles in nationalism.  Yeats' proposal of marriages
were all rebuked.  Her marriage to an intense nationalist had to cast some level of
aspersions into Yeats' understanding and psyche.  At the same time, when the two
eventually consummate after years of friendship, and both of them find this to be
hollow, it brings out the nihilism in Yeats on a personal level.  Examining poems such
as "The Second Coming, "one can see this exploration of the idea of there being no
escape from equally painful ends.  Humans that seek to find an exit from this end are
condemned to futility.  As Yeats experiences this with his relationship with Gonne on an
emotional level, it finds literary resonance within his work.  Such an emptiness can be
seen in his final proposal to Gonne, empty in its intent, filled with attachments,
hoping for rejection, only to cast eyes on her daughter.  This nihilistic and lack of
order in his own relationship with her found ways into his work, one that was not afraid
to embrace "millenial nihilism."