In later years John Murray looked back to 1812 as his ‘annus mirabilis’. In the history of the firm, this year was momentous, the acquisition of the famous Albemarle Street premises second only in importance to the publication of the first two cantos of Byron’s Childe Harold’s Pilgrimage. This essay is concerned with Byron’s relationship with John Murray from that period up until their protracted separation in the early 1820s. It begins by reflecting on the history of what Byron called the ‘natural antipathy’ of authors and booksellers before discussing Murray as a publisher in general terms. The essay asks questions about Byron’s relationship with the man who published his works for over ten years – why was the association successful? Why did it break down? How did Byron’s friends react to Murray’s influence over Byron? It also briefly considers the extent to which Byron’s preoccupation with the nature of his popularity and fame was exacerbated by his association with the massively successful Albemarle Street firm.