||This paper investigates changing gender assignment and exponence at the interface of Old and Middle English by quantitatively analysing the Peterborough Chronicle Continuations. Multivariate Analyses of the results reveal significant facilitatory and inhibitory effects of formal, semantic and extralinguistic variables, supporting and expanding upon previous research. Pronominal exponents have adopted the new, referential ME gender system in virtually all instances by mid-12th-century, while adnominal exponents still display some variation. Among the latter, gender reassignments effecting compliance with the new, referential ME gender system drastically increase from around 40 % in the First Continuation (one scribe, ≈ 1120-1130 CE) to a little over 80% in the Second Continuation (other scribe, ≈ 1155 CE). This indicates an instance of very fast-paced language change, in which a language feature (here: referential gender agreement) develops from a minor variant to the dominating form within one generation only.