Data for: Continuous millennial decrease of the Earth’s magnetic axial dipole

Archaeointensity dataset for the last two millennia, selected from the reassessment of the GEOMAGIA50 database (Brown et al., 2015) and recent estimates that had not yet therein. These data were used in the calculation archaeo_adm_1.3k model, which suggested a continuous decrease of the Earth’s magnetic axial dipole from ~ 750 CE to present.