From the first ideas to the ATLAS TRT

Overview of the R&D work related to the development of the ATLAS Transition Radiation Tracker (TRT) is presented. Significant part of the report will be dedicated to the ideas and side R&D work, which were not necessary realised in a final TRT design, but were directed to find appropriate solutions and might still be interesting for the developments of the transition radiation detectors and gaseous detectors in general.