Contemporary studies on the role of Chief Financial Officers (CFO) create a picture that a radical change in the 1960s created such a role. Predecessor-positions were more focused on transaction-processing aspects of accounting. While historical accounting publications shed some doubt on this assumption, they lack detail on the roles and tasks of such predecessors in the early parts of the twentieth century. Here, we provide a more in-depth analysis of a chief accountant in the period from 1920 to 1940 at Arthur Guinness, Son & Company Ltd. Informed by concepts from Old Institutional Economics, our evidence suggests that the Chief Accountant at Guinness has much in common with a modern-day role. In contrast, we find that even in the first half of the twentieth century before any substantial company law or regulation of accounting, the Chief Accountant was not only doing accounting, but also significantly advising top management, managing risks and interacting with external financiers. This analysis suggests a more gradual development of the role and tasks of internal accountants than that suggested by some contemporary literature.