Brewer's: Gretna Green Marriages
Runaway matches. In Scotland, all that is required of contracting parties is a mutual declaration before witnesses of their willingness to marry, so that elopers reaching the parish of Graitney, or village of Springfield, could get legally married without either licence, banns, or priest. The declaration was generally made to a blacksmith.
Crabbe has a metrical tale called Gretna Green, in which young Belwood elopes with Clara, the daughter of Dr. Sidmere, and gets married; but Belwood was a “screw,” and Clara a silly, extravagant hussy, so they soon hated each other and parted. (Tales of the Hall, book xv.)