The History of the Institute for Theoretical Physics at ETH Zurich reaches back to 1928. The early Institute for Theoretical Physics (ITP) was established with the arrival of Wolfgang Pauli at ETH Zurich in 1928 and was strengthened through the chairs of Res Jost and Markus Fierz in the 1950/60s. The institute expanded in the late 1960s and early 1970s with Walter Hunziker, Klaus Hepp, Christoph Schmid, and Walter Baltensperger representing the fields of mathematical, high energy, and condensed-matter physics. Jost and Fierz were succeeded by Maurice Rice and Jürg Fröhlich in the early 1980s. The presently active generation of professors started with the employment of Gianni Blatter (1993), Gian Michele Graf (1997) and Manfred Sigrist (2001). More recently, the Institute has branched out into new research directions, such as computational physics (Matthias Troyer (2002)), quantum field and string theory (Matthias Gaberdiel (2003) and Niklas Beisert (2011)) and quantum information theory (Renato Renner (2007)). Phenomenological particle physics was established at the professorial level with Charalampos Anastasiou (2007) succeeding Zoltan Kunszt, who retired as a titular professor in 2009. Finally, Thomas Schulthess joined the ITP in 2008 as director of the Swiss National Supercomputing Centre (CSCS), thereby strengthening the computational physics activities.