Swift corresponded with over two hundred of his contemporaries across England and Ireland from a wide variety of social backgrounds and situations. Some of his very best letters are written to women friends, most significantly, Esther Johnson (Stella) and Esther Vanhomrigh (Vanessa). His letters include first-hand accounts of the last four years of English and Irish politics and commentary on the publication of his major works. They also provide painful insight into the declining health of his later years, as when he writes of his ailments in brutally honest terms. This chapter explores the surviving archive of Swift’s correspondence and the evolving style, character, and contents of these documents.