This paper examines the concept of the world elaborated by Heidegger in the early Freiburg lecture courses of the years 1919 to 1923, in which he proposes a renewed conception of phenomenology through a comparison with Husserlian phenomenology. First, I show that although the theme of the lifeworld became central only in late Husserlian works, Husserl began to deal with this concept before 1920. Then, I discuss the way in which Heidegger revisited the issue of the world in the early Freiburg lecture courses by means of a critique of Husserl's analysis. Finally, I point out that the Heideggerian rethinking of the concept of lifeworld is closely connected to the recognition of the immanent historicity of life