Capital in Banking traces the role of capital in US, British, and Swiss banking from the 19th to the 21st century. The book discusses the impact of perceptions and conventions on capital ratios in the 19th century, the effects of the First and Second World Wars, and the interaction of crises and banking regulation during the 1930s and the 1970s. Moreover, it emphasises the origins of the risk-weighted assets approach for measuring capital adequacy and explains how the 2007/2008 crisis led to a renaissance of unweighted capital ratios. The book shows that undisclosed reserves, shareholders' liability, and hybrid forms of capital must be considered when assessing capital adequacy. As the first long-run historical assessment of the topic, this book represents a reference point for publications in economics, finance, financial regulation, and financial history. This title is also available as Open Access on Cambridge Core.