As Breunor (Brunor the Black) is also named as the brother of Dinadan, it seems that Daniel and Breunor were also brothers. Alternatively, it has been suggested that they were simply different names for the same character.
Daniel was also the name of an Arthurian knight in a thirteenth-century German poem by Der Stricker.
Orbellanda | The Legend of King Arthur
La Tavola Ritonda | 1325–1350