Sedley kept his seat in Parliament until his death in 1701. Charles Sedley inherited the title (5th baronet) in 1656 when his brother William died. By his first wife, Lady Katherine Savage, daughter of John Savage, 2nd Earl Rivers, he had only one legitimate child, Catherine, Countess of Dorchester, who later became a mistress of James II of England. After his first wife had been sent to a convent in Ghent on account of a serious mental condition, Sedley tried in vain to obtain a divorce. He met Ann Ayscough, probably around 1670, by whom he had two illegitimate sons, William and Charles Sedley. William died in infancy, the brother Charles was knighted by William III of Orange after the coronation in 1689 and created a baronet in 1702. The relationship with Ann Ayscough lasted to the end of Sedley's life. His reputation as a wit and dissolute was partially responsible for the Sedleys of William Makepeace Thackeray's "Vanity Fair". His most famous song, "Phyllis is My Only Joy", is much more widely known now than the author's name. While Sedley chiefly produced light amatory verse and pastoral dialogues in the 1670s, he turned to satirical epigrams in the 1680s and 1690s. His "Epigrams: or, Court Characters" are modelled on the works of Martial. In his epigram "To Nysus", for example, Sedley describes the function of satire and emphasizes the aggressive mode of satire: "Let us write satyr than, and at our ease / Vex the ill-natur'd Fools we cannot please." At the same time, Sedley translated other specimens of ancient poetry, such as Virgil's Georgics IV, the eighth Ode of the second Book of Horace and three elegies from Ovid's "Amores". Dryden included Sedley's translations from Ovid in the "Miscellany" of 1684. At least three of his poems have been set to music, "Phyllis is My Only Joy" in a glee by John William Hobbs (1799-1877), "Not, Celia, that I Juster Am" in a solo song by the English composer Elizabeth Turner (1700-1756), and "Hears Not My Phillis" (Knotting Song, Z.371) in a solo song by the English composer Henry Purcell (1659-1695).