This study describes the 1200-year history of German quantifying expressions like nîoman anderro > niemand anderer 'nobody else', analyzing the morpho-syntactic developments within the generative framework. The quantifiers examined arose from various lexical sources/categories (nouns, adjectives, and pronouns) but all changed to adjectival quantifiers. These changes are interpreted as a novel type of upward reanalysis from head to specifier, which we associate with degrammaticalization driven by analogy. As for the quantified phrases, most appeared in the genitive in Old High German, indicating a bi-nominal structure. During the Early New High German period, most quantified nouns and adjectives changed to agreement with the quantifier. By Modern German, only quantified DPs and pronouns remain in the genitive. These changes involve downward reanalysis of the quantified elements, being integrated into the matrix nominal depending on the structural size of the quantified phrase. Overall, we conclude that diachronically quantifying expressions may have different syntactic analyses.