Background: Richard Bright (1789–1858) discovered that edema and proteinuria are linked with renal disease. Friedrich Theodor von Frerichs (1819–1885) performed microscopic studies on Bright’s disease and wrote the first German textbook of nephrology. The present contribution analyzes Frerichs’ work. Methods: Frerichs’ career and his book Die Bright`sche Nierenkrankheit und deren Behandlung are examined in terms of contemporary medical knowledge. Results: Frerichs conducted clinical and microscopic studies that led him to conclude that Bright’s disease is a single pathological entity with many possible causes. Frerichs identified three stages through which the condition progresses. Although an oversimplification, Frerichs’ various stages are reflected in the current notion that chronic renal disease, irrespectively of its etiology, relentlessly progresses to end-stage renal failure with common features of tubulointerstitial fibrosis and tubular atrophy. After writing his monograph, Frerichs never touched on renal disease again and is actually better known for his contributions to hepatology. Frerichs was a volatile and difficult person who was not always fair to his students and colleagues. Conclusion: Frerichs put the study of renal diseases on the map in Germany and made the novel observation that chronic renal diseases follow similar morphological patterns despite multiple origins.