This study reconstructs Spain’s national wealth from 1900 to 2017. By combining new sources with existing accounts, we estimate the wealth of both private and government sectors and use a new asset-specific decomposition of the long-run accumulation of wealth. We find that, during the twentieth century, the national wealth-to-income ratio remained within a relatively narrow range—between 400% and 600%—until the housing boom of the early 2000s led to an unprecedented rise to 800% in 2007. Our results highlight the importance of land, housing capital gains and international capital flows as key elements of wealth accumulation.