Who is Lord Derby from The Great War and Modern Memory and what is their importance?

Lord Derby was the British government official who devised the first conscription scheme for World War I in 1916. A lack of volunteer soldiers wasn't filled regardless of the fact that admission standards were lowered, thus, the British government had to resort to a non-voluntary measure. The conscription was accomplished with the Military Service Act. This was said to mark the beginning of the modern world.