The article attempts to provide an explanation of Lord Byron’s disapproval of John Murray’s cruel treat- ment of Lady Morgan, which was clearly expressed in the poet’s letter of February 20, 1818. Accusing the famous publisher of his ungentlemanly callousness, Byron alluded to a harsh review of “France” (1817) by Lady Morgan in the “Quarterly review” launched by Murray in 1809 and famous for its aggressive critical essays on the most celebrated authors of the early 19th century. Lady Morgan was known as an author of some essays, poems and a couple of novels but her literary achievements were much more modest than those of either P. B. Shelley or M. Shelley or other first-magnitude authors severely criticized in the “Quarterly review”, so the anonymous reviewer’s partial attention to her work on France after the Bourbon Restoration meant that the book contained something more than a petticoat gossip collection. The analysis of “France” by Lady Morgan and its perception by British and French critics makes it fair to assume the pro-Irish trendiness of the text, namely an attempt to compare and contrast the life of French and Irish peasants, was the major cause for the attack on the author and her book in Britain. Byron shared Lady Morgan’s concern about the situation in Ireland and remained interested in the Irish question after the Act of Union 1800 even after the curtain had fallen on his official political career, so it is reasonable to suppose that his defence of the author of “France” came out from their common political ground as well as from the poet’s personal negative experience of being zoilised for his “Hours of Idleness” in the “Edinburgh review” a decade earlier.