This paper offers an overview of the history of medial NP-adjuncts from Old English to Present-Day English. In Present-Day English, adverbs are perfectly grammatical in a position between the subject and the main verb ('He recently left for London') whereas NP-adjuncts are at best stylistically marked in this position ('(*)He tomorrow leaves for London'). The paper shows that while medial placement of NP-adjuncts has been considerably less frequent as compared to adverbs ever since around 1500, the contrast was initially much stronger in clauses with finite main verbs than in clauses with finite auxiliaries. It is only in the 19th century that medial placement becomes equally marked in both contexts. These developments are accounted for in terms of processing constraints disfavouring the use of medial NP-adjuncts and a structural reanalysis of NP-medial adjuncts in Late Modern English.