In this article Erika Fischer-Lichte argues that, since the beginning of the twentieth century, in different parts of the world, modern theatre was invented by way of interweaving cultures in performance. Different examples from the early twentieth century and the 1990s show how theatre acted as a laboratory for testing and experiencing the potential of cultural diversity. An innovative performance aesthetics enabled the exploration of the emergence, stabilization, and destabilization of cultural identity, merging aesthetics with politics.