Who is Georg Wilhelm Friedrich Hegel from The Society of the Spectacle and what is their importance?

Georg Wilhelm Friedrich Hegel was a German philosopher. Widely published, his philosophy has been immensely influential on Western culture. Beside Marx, Hegel's philosophy is the most dominant presented in the text, though of course this would be natural for the time and place of writing. A basic familiarity with Hegel is nearly a prerequisite to understanding major portions of the text.