''Tread softly because you tread on my dreams'' is one of the most well-known and repeated lines of poetry ever written. Less haunting, but still so relevant: ''Life is a long preparation for something that never happens.''W B Yeats was one of the foremost figures of 20th century literature. Winner of a Nobel prize, he was also a political figure, and, as is evident from his earlier work, fascinated by Irish folklore and the occult. He was also deeply affected by the First World War and the Anglo-Irish and Irish civil wars. It is a testament to the greatness of Yeats'' poetry that he attempts to bear witness to these emotional and historical forces.This perfectly pitched collection includes some of the greatest poetry of the 20th century.