Doldanim, Doldamer, Doldan, Doldau, Dolmad
The King of Gotland (Gothland) or Jutland who, along with Gunphar, the King of the Orkneys, came to pay homage to Arthur, having heard of his prowess and fearing his might. He surrendered to King Arthur rather than be conquered by him.
He later assisted Arthur in the conquest of France and in the Roman War.
Sources
Historia Regum Britanniae | Geoffrey of Monmouth, c. 1138
Roman de Brut | Wace, c. 1155
Brut | Layamon, late 12th century to mid-13th century