Killybegs was incorporated by a charter of 13 James I, 1616, on the usual pattern of a portreeve/provost, 12 burgesses and the commonalty, about whose municipal activity little is known. It was entirely in the hands of successive branches of the Conyngham family, and from 1782 until his death in 1796 of Col. William Burton-Conyngham (0303), who inherited it from his uncle, Earl Conyngham. On his death in 1796 it devolved under the will of his uncle, Henry, 1st Earl Conyngham (of the first creation) (0464) to his nephew, Henry, 3rd Baron Conyngham (of the second creation) and in 1816 1st Marquess Conyngham, who received the £15,000 compensation for its disfranchisement in 1800.