In the mythological writings of William Blake, Grodna is the third son of Urizen.
[1] In Chapter VIII of The Book of Urizen his birth is described: His identification is with the classical element Earth, in the alignment of Urizen's four sons.
[1]
The birth of the four sons of Urizen, depicted in
The Book of Urizen
, copy G, collection the Library of Congress. Grodna appears in the bottom right