Theodor Adorno and Max Horkheimer were two of the most prominent figures in The Frankfurt School, a group of German intellectuals that worked together during the 1920's to develop a critical theory of society with Marxist influences.
Adorno and Horkheimer's work is based on the legacy of Karl Marx and was aimed at the critique of Western industrialized-capitalist society. Unlike traditional Marxism in which the economy determines everything, Adorno and Horkheimer and their friends at the Frankfurt School sought to describe the interconnections of economy with culture, psychology, media and other intricate factors through which capitalism functions. For this end they offered a combination of different disciplines and traditions of thought, bringing Marx and Sigmund Freud together in one theory aimed at explaining repressive mechanisms in society.
Like many members of the Frankfurt School, Adorno and Horkheimer were Jewish, which led them to flee Nazi Germany in the 1940's and migrate to the United States. Although not as bad as Fascist Nazism, Adorno and Horkheimer had to suffer living Capitalism in its American extreme. They're later philosophy is very bleak as they developed a view of modern society as controlled by massive anonymous systems of power and control which have no humanity in them and which reduce both society and the individual into what Marcuse called "The one-dimensional man" (such courses of thought led Adorno and Horkheimer to coin their famous term "culture industry" (see also a simple definition of culture industry) that broadly says the culture is not only industrially produced but also industrially producing minds).
During their work in capitalist exile Adorno and Horkheimer focus on their critique of the failed promise Enlightenment carried with it to liberate people. One of the better known results of Adorno and Horkheimer's collaboration is their book "Dialectic of Enlightenment" publish shortly after the war in 1947.
Adorno and Horkheimer remain highly influential figures in the tradition of critical theory and neo-marxist, media studies, sociology and more.
Some books on and by Adorno and Horkheimer: