The global aim of this collaborative Spain-US project was to analyze the deformation, recrystallization, and damage mechanisms of several advanced Mg alloys fabricated by rare-earth alloying. Several alloys were generously donated by the Helmholtz Zentrum Geesthacht (Geesthacht, Germany) for this research. A combination of microstructure and mechanical characterization techniques were utilized to achieve the desired objective. The team at Michigan State University (MSU, US) carried out in-situ testing in an scanning electron microscope (SEM) in order to obtain quantitative local evidence of the operative slip and twinning systems as well as of the kinetics of recrystallization. The Imdea Materials team performed the microstructural characterization and ex-situ testing of the mentioned alloys. Finally, the UPM team utilized continuum-based plasticity modeling and mechanistic models to simulate the deformation and fracture behavior of the Mg-rare earth alloys.