Killyleagh was enfranchised by a 1613 charter of 10 James I at the petition of the inhabitants of the town. It had a provost and 12 free burgesses elected by the inhabitants of the town. The borough of Killyleagh originally came under the influence of the Hamiltons; it then passed through a series of marriages to Dorcas, daughter and eventual heiress of James Stevenson (1997) of Killyleagh, who in 1751 married Sir John Blackwood, 2nd Bt (0148). The Blackwoods sustained their interest in Killyleagh, which was a small fishing village on Strangford Lough, by such activities as in 1765 obtaining a parliamentary grant of £1,200 to build a pier. They had a Presbyterian background - Sir John was a graduate of Glasgow University - and they usually returned members of their family or friends, which probably helped to ensure their popularity. Killyleagh was completely under their control. Sir John was returned for Bangor in 1768 and again in 1790. On both occasions he may have been Provost of Killyleagh and therefore unable to return himself. Killyleagh was disfranchised at the Union and the £15,000 was paid to Sir James Blackwood (0147), who in 1808 succeeded his mother as Lord Dufferin.