This paper discusses the evolution of Ngen+N compounds (e.g. nan regnes dropa ‘no rain’s drop’) into N+N compounds (i.e. the equivalent of ‘no rain drop’) between the Old and the Middle English period. The contribution first describes various types of pre-nominal genitive constructions found in Old English, then illustrates the extension of genitive –es to all declensions and plurals in pre-nominal genitive constructions – where it was re-analysed as clitic or phrasal suffix-- and finally explains how the loss of genitive marking confined to Ngen+N compounds was prompted by the re-organization of the inflectional morphology, whereby, among other things, genitive –es was unselectively attached to all nominal roots.