This article looks at the origins and uses of contrastive hierarchies in Old English diachronic phonology, with a focus on the development of West Germanic vowel systems. I begin with a rather enigmatic remark in Richard Hogg's A grammar of Old English (1992), and attempt to trace its provenance. We will find that the trail leads back to analyses by some prominent scholars that make use of contrastive feature hierarchies. However, these analyses often appear without context or supporting framework. I will attempt to provide the missing framework and historical context for these analyses, while showing their value for understanding the development of phonological systems. I will show that behind these apparently isolated analyses there is a substantial theoretical edifice that once held a central role in synchronic as well as diachronic phonological theory, and which is still capable of providing insights into the workings of phonology.