In this paper we investigate the initial stages of epitaxial growth of Ge on Si(1 1 1) and the impact of growth temperature on strain evolution in situ by reflection high energy electron diffraction (RHEED) for temperatures between 200 degrees C and 400 degrees C. The change in surface morphology from a flat wetting layer to subsequent islanding that is characteristic for Stranski-Krastanov growth is monitored by spot intensity analysis. The corresponding critical layer thickness is determined to 3.1 < d(c) < 3.4 ML. In situ monitoring of the strain relaxation process reveals a contribution of the Si(1 1 1) 7 x 7-surface reconstruction to the strain relaxation process. High resolution transmission electron microscopy confirms that the Ge islands exhibit a high degree of structural perfection and an ordered interfacial misfit dislocation network already at a growth temperature of 200 degrees C is established. The temperature dependency of island shape, density and height is characterized by atomic force microscopy and compared to the RHEED investigations. (C) 2016 Elsevier B.V. All rights reserved.