Attila Abramowski, Felix A. Aharonian, Faical Ait Benkhali, A. G. Akhperjanian, Ekrem Oǧuzhan Angüner, Michael Backes, Shangkari Balenderan, Arnim Balzer, Anna Barnacka, Yvonne Becherini, J. Becker Tjus, David Berge, Sabrina Bernhard, K. Bernlöhr, E. Birsin, Jonathan Biteau, Markus Boettcher, Catherine Boisson, J. Bolmont, Pol Bordas, Johan Bregeon, Francois Brun, Pierre Brun, Mark Bryan, Tomasz Bulik, Svenja Carrigan, Sabrina Casanova, Paula M. Chadwick, N. Chakraborty, R. Chalme-Calvet, Ryan C. G. Chaves, M. Chretien, Sergio Colafrancesco, Gabriele Cologna, Jan Conrad, C. Couturier, Y. Cui, I. D. Davids, B. Degrange, C. Deil, P. dewilt, A. Djannati-Ataï, W. Domainko, A. Donath, G. Dubus, K. Dutson, J. Dyks, M. Dyrda, T. Edwards, Kathrin Egberts, P. Eger, P. Espigat, C. Farnier, S. Fegan, F. Feinstein, M. V. Fernandes, D. Fernandez, A. Fiasson, G. Fontaine, A. Foerster, M. Fuessling, S. Gabici, M. Gajdus, Y. A. Gallant, T. Garrigoux, G. Giavitto, B. Giebels, J. F. Glicenstein, D. Gottschall, M. -H. Grondin, M. Grudzinska, D. Hadasch, S. Haeffner, J. Hahn, J. Harris, G. Heinzelmann, G. Henri, G. Hermann, O. Hervet, A. Hillert, James Anthony Hinton, W. Hofmann, P. Hofverberg, M. Holler, D. Horns, A. Ivascenko, A. Jacholkowska, C. Jahn, Marek Jamrozy, M. Janiak, F. Jankowsky, I. Jung-Richardt, M. A. Kastendieck, Krzysztof Katarzynski, Uli Katz, S. Kaufmann, B. Khelifi, M. Kieffer, S. Klepser, D. Klochkov, W. Kluzniak, D. Kolitzus, Nu. Komin, K. Kosack, S. Krakau, F. Krayzel, P. P. Krueger, H. Laffon, G. Lamanna, J. Lefaucheur, V. Lefranc, A. Lemiere, M. Lemoine-Goumard, J. -P. Lenain, T. Lohse, A. Lopatin, C. -C. Lu, V. Marandon, Alexandre Marcowith, R. Marx, G. Maurin, N. Maxted, M. Mayer, T. J. L. McComb, J. Mehault, P. J. Meintjes, U. Menzler, M. Meyer, A. M. W. Mitchell, R. Moderski, M. Mohamed, K. Mora, Emmanuel Moulin, T. Murach, M. de Naurois, J. Niemiec, S. J. Nolan, L. Oakes, H. Odaka, S. Ohm, B. Opitz, M. Ostrowski, I. Oya, M. Panter, R. D. Parsons, M. Paz Arribas, N. W. Pekeur, G. Pelletier, P. -O. Petrucci, B. Peyaud, S. Pita, H. Poon, G. Puehlhofer, Michael Punch, A. Quirrenbach, S. Raab, I. Reichardt, A. Reimer, Olaf Reimer, M. Renaud, R. de los Reyes, F. Rieger, C. Romoli, S. Rosier-Lees, G. Rowell, B. Rudak, C. B. Rulten, V. Sahakian, D. Salek, David M. Sanchez, A. Santangelo, R. Schlickeiser, Fabian Schuessler, A. Schulz, U. Schwanke, S. Schwarzburg, S. Schwemmer, H. Sol, F. Spanier, G. Spengler, F. Spies, L. Stawarz, R. Steenkamp, Christian Stegmann, F. Stinzing, K. Stycz, Iurii Sushch, J. -P. Tavernet, T. Tavernier, A. M. Taylor, R. Terrier, M. Tluczykont, C. Trichard, K. Valerius, Christopher van Eldik, B. van Soelen, G. Vasileiadis, J. Veh, C. Venter, A. Viana, P. Vincent, J. Vink, H. J. Voelk, F. Volpe, M. Vorster, T. Vuillaume, S. J. Wagner, P. Wagner, R. M. Wagner, M. Ward, M. Weidinger, Q. Weitzel, R. White, A. Wierzcholska, P. Willmann, A. Woernlein, D. Wouters, R. Yang, V. Zabalza, D. Zaborov, M. Zacharias, A. A. Zdziarski, Alraune Zech, H. -S. Zechlin, Y. Fukui

• Diffuse gamma-ray emission is the most prominent observable signature of celestial cosmic-ray interactions at high energies. While already being investigated at GeVenergies over several decades, assessments of diffuse gamma-ray emission at TeVenergies remain sparse. After completion of the systematic survey of the inner Galaxy, the H.E.S.S. experiment is in a prime position to observe large-scale diffuse emission at TeVenergies. Data of the H.E.S.S. Galactic Plane Survey are investigated in regions off known gamma-ray sources. Corresponding gamma-ray flux measurements were made over an extensive grid of celestial locations. Longitudinal and latitudinal profiles of the observed gamma-ray fluxes show characteristic excess emission not attributable to known gamma-ray sources. For the first time large-scale gamma-ray emission along the Galactic plane using imaging atmospheric Cherenkov telescopes has been observed. While the background subtraction technique limits the ability to recover modest variation on the scale of the H.E.S.S. fieldDiffuse gamma-ray emission is the most prominent observable signature of celestial cosmic-ray interactions at high energies. While already being investigated at GeVenergies over several decades, assessments of diffuse gamma-ray emission at TeVenergies remain sparse. After completion of the systematic survey of the inner Galaxy, the H.E.S.S. experiment is in a prime position to observe large-scale diffuse emission at TeVenergies. Data of the H.E.S.S. Galactic Plane Survey are investigated in regions off known gamma-ray sources. Corresponding gamma-ray flux measurements were made over an extensive grid of celestial locations. Longitudinal and latitudinal profiles of the observed gamma-ray fluxes show characteristic excess emission not attributable to known gamma-ray sources. For the first time large-scale gamma-ray emission along the Galactic plane using imaging atmospheric Cherenkov telescopes has been observed. While the background subtraction technique limits the ability to recover modest variation on the scale of the H.E.S.S. field of view or larger, which is characteristic of the inverse Compton scatter-induced Galactic diffuse emission, contributions of neutral pion decay as well as emission from unresolved gamma-ray sources can be recovered in the observed signal to a large fraction. Calculations show that the minimum gamma-ray emission from pi(0) decay represents a significant contribution to the total signal. This detection is interpreted as a mix of diffuse Galactic gamma-ray emission and unresolved sources.…