Jane Austen’s beloved naval brother, Charles Austen (1779–1852), had a significant impact on her literary career.We find probable traces of him in the male characters appearing in Mansfield Park (1814) and Persuasion (1818), and he is said to have offered naval vocabulary to help his sister revise the second edition of Mansfield Park (1816). In addition to his impact during Jane’s lifetime (1775–1817), Charles played a role in sustaining her posthumous celebrity, modest as it was at first. Two previously unpublished brief letters by him—and references to him in other correspondence—offer an opportunity to speculate about his role in supporting his late sister’s literary reputation.