"With recourse to archival, printed primary, and secondary sources, this paper reconstructs global real interest rates on an annual basis going back to the 14th century, covering 78% of advanced economy GDP over time. I show that across successive monetary and fiscal regimes, and a variety of asset classes, real interest rates have not been ‘stable’, and that since the major monetary upheavals of the late middle ages, a trend decline between 0.6–1.6 basis points per annum has prevailed. A gradual increase in real negative-yielding rates in advanced economies over the same horizon is identified, despite important temporary reversals such as the 17th Century Crisis. Against their long-term context, currently depressed sovereign real rates are in fact converging ‘back to historical trend’ — a trend that makes narratives about a ‘secular stagnation’ environment entirely misleading, and suggests that — irrespective of particular monetary and fiscal responses — real rates could soon enter permanently negative territory. I also posit that the return data here reflects a substantial share of ‘non-human wealth’ over time: the resulting R-G series derived from this data show a downward trend over the same timeframe: suggestions about the ‘virtual stability’ of capital returns, and the policy implications advanced by Piketty (2014) are in consequence equally unsubstantiated by the historical record."