This thesis seeks to establish how the concept of space informed and characterised the art of the Vienna Secession between 1897 and 1905. This question is examined through the practices and concerns of founding Secession artist and designer Alfred Roller (1864- 1935). Roller is better-known in his role as stage designer at the Vienna Court Opera from 1903, in partnership with its music director, Gustav Mahler. A central argument of this thesis is that Alfred Roller demonstrated the pursuit of a synthetic aesthetic which transposed Wagner’s ideas of the Gesamtkunstwerk to other spheres or spaces of art. Roller’s contribution to art and design histories of the Vienna Secession has been little recognised. This thesis argues that Roller, as Secession founder, editor of and contributor to the Secession art periodical, Ver Sacrum (1898-1903), and designer of Secession exhibitions was a pivotal figure in the achievements of the Vienna Secession in its early years. An analysis of Roller’s roles within the Secession, and at the Vienna Court Opera, indicate a turning point in modern practice in three seemingly disparate spaces of art: the design of the art periodical, the design of exhibitions, and stage design, notably for the music dramas of Wagner. The thesis reveals that Alfred Roller was an emblematic figure in the overstepping of artistic boundaries, a distinction attributed to Vienna's artistic and cultural endeavours at the turn of the century. This thesis is tested through an examination of these three spaces of art which form the subjects of its central chapters. The two-dimensional spaces of the art periodical Ver Sacrum, and the interior spaces of the Secession Haus (1898-), the exhibition pavilion, were designed by the Secession in their pursuit and presentation of new forms of modern art and design. It is already well established that Roller brought innovative new practices to the revivification of the staging of Wagner’s music dramas, amongst other works, to the Vienna Court Opera. However, here it is argued that Roller invested the spaces of the stage with concerns which were shaped by his Secession practices, demonstrating the fluidity of his aesthetic principles from two to three dimensions.