This paper emphasises the importance of business history for analysing labour market structures and practices in financial markets in the United Kingdom and more particularly at Barclays De Zoete Wedd (BZW), the international investment banking arm of the British bank Barclays plc. By adopting an historical perspective, this study departs from existing literature and presents new explanations concerning the importance of the relationship between business history and the origins and functions of internal labour markets. The theoretical framework elaborated involves a model and a timeline in its analysis, which highlights significant emerging patterns in internal labour markets that become evident over time. The study reveals evidence that, contrary to the arguments raised by scholars which suggest a decline in internal labour market practices in favour of a return to a more market-based system, internal labour market arrangements continue to apply to an organisation such as BZW at all stages in its organisational development.