This research focuses on the Loumar deformation which affected the NE slope of the Gavar anticline (Zagros Mts., Iran). The landslide evolution is strictly related to the growth of the fold and to the evolution of the Seymareh river drainage system. In this regard, we infer the Quaternary tectonic and landscape evolution of the fold, as well as the chronology of the events that led to the deformation and following failure, through geomorphometric analyses, as well as field surveying and OSL dating of geomorphic markers. Assuming a block uplift model, the drainage network of Gavar fold recorded 1.3{plus minus}0.1 Myr of tectonic history that describes the lateral propagation of the fold towards NW. According to the inversion history, the formation of a parasitic fold at 0.16 {plus minus} 0.015 Ma led to a meander abandonment in the ancient course of the Seymareh River, thus favoring the kinematic release of a large rock mass along the flank of the fold. The latter allowed the initiation of the deformation, which culminated in a huge rockslide at 5.52{plus minus}0.36 ka, as constrained by the OSL age of sediments deposited upstream in a pond caused by the partial damming of the river. Finally, InSAR techniques were applied by processing 181 satellite Sentinel-1 radar images of the ascending and descending orbit, spanning from 16 May 2016 to 21 November 2019. It has been observed that the rockslide is still moving downslope with a maximum displacement rate of 7.5 mm y^-1 in the trench zone.