King Doniert's Stone (Cornish: Menkov Donyerth Ruw)[1] consists of two pieces of a decorated 9th-century cross, near St Cleer on Bodmin Moor, Cornwall.

[4] The inscription is thought to refer to the local ruler Dumgarth (or Dwingarth), who is recorded in the early Welsh chronicle known as the Annales Cambriae as having drowned in around 875 AD.

[5] The southern cross, sometimes referred to as the Other Half Stone, is 2.1 metres (6 ft 11 in) high with a panel of interlace decoration on the east face, a broken mortise slot at the top and a plinth at the bottom.

Mr Charles Spence published in the Transactions of that society a paper entitled Iter Cornubiense in which he details the proceedings of the work.

After raising Doniert's stone and placing it in an erect position, a mass of granite no less than two tons and a half in weight, the workmen were directed to dig down by the side of the other monolith.