Nature Astronomy, Published online: 17 August 2026; doi:10.1038/s41550-026-02931-5 By studying the dynamical properties, age and metallicity of globular clusters in the inner Galaxy, the authors found evidence of a massive dwarf galaxy that was accreted by the Milky Way 1.8 billion years earlier than the Gaia-Sausage-Enceladus merger.