Jürgen Habermas is a late 20th Century philosopher of social criticism. Though he has ties to Max Horkheimer's Frankfurt School, he was only a member for four years.
Habermas was born in Düsseldorf, in the west German lowlands, on June 18, 1924. He grew up in Gummersbach; his father was director of Gummersbach's Chamber of Commerce. Though he would later be known for his criticism of the pressures of the bourgeois market system, Habermas's background was clearly about as bourgeois as you can get. Habermas was even in the Hitler Jugend.
Habermas was educated at the University of Gottingen (starting in 1949) and also at the Universtiy of Bonn. He also did one summer session at the University of Zürich. He focused on the philosophy of Immanuel Kant, Wilhelm Dilthey, and Martin Heidegger (who was very popular at that time). His doctoral dissertation was entitled "The Absolute and History: The Duality in Schelling's Thought." He was not widely regarded as having much potential in philosophy, particularly because of his peculiar disability (he has a cleft palate, making it very difficult to understand his speech).
In 1955, Habermas joined the Frankfurt School* as Theodor Adorno's assistant. However, with the publication of The Structural Transformation of the Public Sphere, he was pushed out by Horkheimer. Though any attempt to discern why Horkheimer felt the need to get rid of Habermas would be purely speculation, it was most likely a combination of pride (here was a young upstart who was going to recieve more publicity** than the school had yet gotten) and professional disagreement on the issue of methodology -- Habermas had written a book whose argumentation rested mainly on the presentation of historical fact (an approach Horkheimer thought catered to the expectations of the establishment), rather than abstract dialectical criticism (Horkheimer's own weapon of choice). In any event, after 1959 Habermas was no longer a member of the Frankfurt School; instead he went on to become the most famous philosopher alive today.***
As one would expect from a pupil of the Frankfurt School, Habermas is a defender of liberalism and the ideals of the Enlightenment. In particular, he maintains (against criticism from postmodernist corners) that a knowledge of norms is possible. His innovation is in positing that we can understand norms in relation to the "ideal speech situation," that is to say that our knowledge of proper behaviour stems primarily from our sense of how to understand others and be understood ourselves.
The books Habermas has written (along with the year they were published in German and the year they were translated into English:
Habermas is still alive, and as far as I know, still lecturing. According to Peter Pan he is set to receive the Friedenspreis des deutschen Buchhandels, an award from German publishers, and he has recently published a new book, Zeit der Übergänge (Time of Transitions).
* Note to self: Kudos for resisting the urge to call them "the Frankfurters" like some bad German punk band. Keep up the good work.
** Anyone familiar with Structural Transformation need not have the irony of this pointed out.
*** Though Chomsky and Derrida might be able to give him a run for his money. Michel Foucault was also very much the proverbial hot shit until he passed away in 1984.