Abstract In this article we provide a practical demonstration of how syntactically annotated corpora (treebanks), particularly the English Historical Parsed Corpora Series, can be used to investigate research questions with a diachronic depth and synchronic breadth that would not otherwise be possible. The phenomenon under investigation is split coordination, in which two parts of a conjoined constituent appear separated in the clause (e.g., and this is where my aunt lives and my uncle ). It affects every type of coordinated constituent (subject/object DPs, predicate and attributive ADJPs, ADVPs, PPs and DP objects of P) in Old English (OE); and it, or a superficially similar construction, occurs continuously throughout the attested period from approximately 800 to the present day. Despite its synchronic range and diachronic persistence, split coordination has received surprisingly little attention in the diachronic literature, with the exception of Perez Lorido’s (2009) limited study of split subjects in eight OE texts. Its modern counterpart is most frequently analysed as Bare Argument Ellipsis (BAE). Although the OE and Present-Day English constructions appear superficially similar, we show that not all of the OE data is amenable to a BAE analysis. We bring to bear different types of evidence (structural, discourse/performance effects, rate of change, etc.) to argue that split coordination in fact represents two different constructions, one of which remains stable over time while the other is lost in the post-Middle English period.