William Butler Yeats was an Irish poet and one of the foremost figures of 20th-century literature. A pillar of both the Irish and British literary establishments, in his later years he served as an Irish Senator for two terms. Yeats was a driving force behind the Irish Literary Revival and, along with Lady Gregory, Edward Martyn, and others, founded the Abbey Theatre, where he served as its chief during its early years. In 1923, he was awarded the Nobel Prize in Literature as the first Irishman so honoured for what the Nobel Committee described as "inspired poetry, which in a highly artistic form gives expression to the spirit of a whole nation". Yeats is considered to be one of the few writers who completed their greatest works after being awarded the Nobel Prize; such works include The Tower (1928) and The Winding Stair and Other Poems (1933).