Who is Siegfried Sassoon from The Great War and Modern Memory and what is their importance?

Siegfried Sassoon was an author. He was born in 1886 in Kent. Sassoon was of Jewish descent, and he had a brother who died at Gallipoli in 1915. Educated at Marlborough College and at Clare College, Sassoon left Cambridge before taking a degree. He loved horses and was quite a horseman. He served in the cavalry in August 1914.