If the Oxford Movement describes a period from 1833-1845, why were "Macspaunday" called the four musketeers of the Oxford Movement?"Macspaunday"...

Aside from its geographical focus, the Oxford Group of the 1920s and 1930s shares little in common with the nineteenth-century Oxford Movement.  The Oxford Movement (1833-1845) was an attempt on the part of Roman Catholics to reform the Anglican Church, using the argument that the Church of England was essentially a "catholic" church.  The Oxford Group of early twentieth century, however, refers to the literary movement headed by "Macspaunday," a term that combined the names of its four leading poets:  Louis MacNeice, Stephen Spender, W.H. Auden, and Cecil Day Lewis.

Their central role in the Oxford Group resulted in their being called the "four musketeers of the Oxford Group."  The four poets at the heart of the Oxford Group espoused Modernism, particularly ideas connected with T.S. Eliot.  W.H. Auden, widely considered the most important member of the group, received the greatest acclaim.  While still an undergraduate, Stephen Spender published some of his poems, and year later, Auden published Poems with Faber and Faber, of whom T.S. Eliot was the director.  Throughout the 1930s, Auden and the other members of the Oxford Group published volumes of poetry, notable among them being The Orators (1932).  Auden also published The Dog Beneath the Skin (1935), a satirical look at England.

While the Oxford Group extended beyond the figures of Auden, MacNeice, Day Lewis, and Spender, including Christopher Isherwood among others, the "four musketeers," especially W.H. Auden, served as the voice of the group.