The Battle of Arkinholm was fought on 1 May 1455, at Arkinholm near Langholm in Scotland, during the reign of King James II of Scotland. Although a small action, involving only a few hundred troops, it was the decisive battle in a civil war between the king and the Black Douglases, the most powerful aristocratic family in the country. As the king's supporters won it was a significant step in the struggle to establish a relatively strong centralised monarchy in Scotland during the Late Middle Ages.