After the decline of the debates about the "post-modernism" and the advance of "globalization" as major signifiers of our time, the discourse on modernity and modernism have re-emerged strongly in the current intellectual landscape. The provocative occurrence of Jean Lyotard that any work of art must be post-modern before it can become genuinely modern, it has become reality in a way that he could hardly foresee. The various articles that make up this work of Andreas Huyssen show that modernity and modernism, with all its historical and geographical complexities remain a key signifiers for anyone trying to understand where we came from and where it may go: the century XX to XXI century. After a first half where the question of a post-modernity in a geographically expanded (eg in cities like Barcelona and Paris, Prague and Vienna, Berlin and Munich, London and St. Petersburg field modernism is addressed, or the work of artists such as Guillermo Kuitca or Doris Salcedo), Andreas Huyssen develops in the second thematic block (with writings on WG Sebald, the stubborn images of 11-S or memorials in Berlin and New York) interest not only policy memory as manifested in cultural objects, but also the relationship between history and memory, a subject that has become one of the biggest bones of contention of our time, as in the case of intense political debate, legal and cultural on the Civil War and the Franco regime in Spain produced today. In conclusion, Huyssen shows that the discourse on traumatic historical memory and can not be limited to a country and its borders. As with the discourse of the trauma itself, this debate has become something fundamentally palimséstico and repetitive, to the point that multiple discourses of historical memory intertwine and overlap worldwide across borders, bouncing one in the other either hiding and forgetting historical memory itself, either reinforcing it.