Abstract
In the context of hierarchical galaxy assembly, both globular clusters and dwarf galaxies serve as indispensable probes of the formation of our Milky Way. The chemical composition of stars within these ancient structures plays a pivotal role in constraining their chemical enrichment history. Each possesses its own chemical peculiarities; for instance, dwarf galaxies contain stars with low [alpha/Fe] compared to Galactic halo objects of the same metallicity. Meanwhile, globular clusters house multiple stellar populations characterized by their light element abundances. To date, most studies have focused almost exclusively on elemental abundances, however, nucleosynthesis operates at the isotopic level. In this talk, I will discuss how Mg isotope ratios shed light on both the accreted dwarf galaxy component of our Milky Way and the light element enhanced populations within globular clusters. This reveals contributions from SNeII and AGB stars that cannot be discerned through element abundances alone.