The DHS 20 program by Hirche for Christian Holzäpfel unveiled in 1956 at the Cologne furniture fair, included objects which were aesthetically very close to the furniture collections from Knoll International. This proximity was no coincidence: Knoll were strongly influenced by Mies van der Rohe whom Hirche cooperated with in the immediate pre-War years, and, logically, post-War continued to develop his pre-War understandings. In addition both Mies and Hirche were both active members of the pre-War Deutsche Werkbund, and post-War Herbert Hirche felt himself to be committed to this tradition.The DHS 20 was followed a year later by the DHS 30 office furniture system, supplemented by a version with fine wood veneer for the executive area known as the DHS 300.