Hydrothermal monazite-(Ce) from open clefts/fissure veins in the Alps was utilized as a complimentary tool for dating brittle-ductile/brittle deformation. It may preserve evidence of several crystallization events, commonly over 4-7 Ma, up to ~20 Ma. Monazite-(Ce) crystallizes within ~350-200 °C during tectonic and/or fluid flux events disequilibrating the fluid-crystal/rock chemistry within a cleft. It resists alteration/diffusion under prevailing p-T conditions, but may experience new/re-crystallization or dissolution-reprecipitation. Ages from the northeastern Alps, Austria, of 90-70 Ma cover near peak metamorphism during Eo-Alpine collision over orogenic collapse to extension. In the eastern Tauern Window, ages date metamorphic dome exhumation during Alpine collision at ~19-15 Ma. In the Lepontine dome area ages of ~19-5 Ma date early exhumation, doming and a later change after 12 Ma from thrusting to strike-slip movements, linked to a progressive concentration of deformation towards the extended Rhone-Simplon/Penninic Front fault system in the Mont-Blanc/Aiguilles-Rouges, Aar and western Lepontine areas.