The international symposium BRNO THEATRALIA CONFERENCE 2021, hosted by the Department of Theatre Studies, Masaryk University (Brno, Czech Republic), is dedicated to historical avant-gardes and their development in Czechoslovakia and Europe. The aim is to reassess the Czech interwar theatre, built at the crossroads of the European avant-garde. This aim is closely related to the specific features of the avant-garde Theatres in Europe (France, Germany, Italy, Spain, Russia...) and to the way the individual European countries influenced one another in this respect. The conference focuses on historical avant-gardes in both Czech and European theatrical milieu from the perspectives of theatre studies, performing arts, dance, music, art history, architecture, cinema, photography, ethnography and folklore, literature, translation, etc. The conference was planned to take place in 2020 on the occasion of the hundredth anniversary of the foundation of the association of Czech avant-garde artists Devětsil. Founded in October 1920 in Prague, Devětsil (”butterbur”), the most influential Czech avant-garde circle, united artists across a wide range of both artistic and non-artistic fields: from architecture to performance, and from aesthetics to sociology. Its members, such as Karel Teige, Vítězslav Nezval, Toyen, Jindřich Štyrský, Adolf Hoffmeister, Josef Chochol, Jiří Frejka, Jindřich Honzl, Emil František Burian, Jiří Voskovec, and Jan Werich, were constantly following European avant-garde trends.