Two entries with the name Joshua.
Joseus, Josué, Josue
With Alain, he journeyed to the Strange Land, converted King Kalafes of the Terre Forraine, and established Corbenic (Carbonek), the Grail Castle. He inherited the land upon Kalafes’s death, and became the first Grail King. He married Kalafes’s daughter and passed the throne to his son, Aminadap (Aminabad). He succeeded his brother Alain as guardian of the Grail, following the normal line of descent for the Fisher Kings.
Vulgate Estoire del Saint Graal | 1220-1235
Cronica sive Antiquitates Glastoniensis Ecclesie | John of Glastonbury, mid-14th century