William Butler Yeats was an Irish poet and playwright known for his use of symbolism and exploration of Irish nationalism. This document provides biographical details on Yeats and summarizes some of his major poems and themes. It discusses how Yeats adopted different personas and addressed nationalism, colonialism, and the construction of Irish identity. His poems "The Lake Isle of Innisfree" and "Easter 1916" imagine an idealized Ireland and reflect on the 1916 Easter Rising. "The Second Coming" presents a vision of the end of one historical epoch and the chaotic birth of another, represented by a frightening beast-like figure.