According to Etienne de Rouen, author of Draco Normannicus, the famed English monarch (reigned 1154-1189) corresponded with Arthur who, having been healed by Morgan, was immortal and living in an antipodal kingdom.
Henry was in the process of conquering Brittany from Count Rollandus when Arthur sent a letter to Henry in an attempt to intervene on Rollandus’s behalf. Arthur supposedly granted stewardship of Britain to Henry II, but retained ultimate sovereignty for himself. Henry ignored the letter and evidently suffered no consequences.
The Post-Vulgate Merlin continuation notes that Henry II removed statues of Perceval and Clamadeu from the battlefield at Beaurepaire and stored them in his treasury at St. Lorent. According to Giraldus Cambrensis, it was Henry who told the Glastonbury monks where to find Arthur’s body. Henry had apparently learned of the location from a bard.
Sources
Draco Normannicus | Étienne de Rouen, c. 1169
De Principis Instructione | Giraldus Cambrensis, c. 1193
Post-Vulgate Suite du Merlin | 1230-1240