Power of the Balrogs and Elven Kings

[Kirinki54]

Originally posted by Inoldonil
Of course Gothmog was the greatest of the Balrogs. He seems lesser than Durin's Bane because the only extant narratives dealing with him is when the Balrogs were a different Race altogether, when they were bred by Morgoth and were far less in stature and power.

Just curious, did Morgoth actually breed Balrogs? I imagined they were Maiar?