Corsar Thal was the Emperor of Thanagar.
The son of Thal Provis, brother of Shayera Thal and adoped brother of Katar Hol, Corsar was next in line to become emperor. Like all other Thanagarians, Corsar lost his wings due to a Daemonite virus and after the death of his father, became emperor. Corsar became obsessed with the idea of finding the Nth Metal and was overjoyed when he discovered, due to Katar, that the Nth Metal worked. However, in the process of finding it, and that too just a little, Corsar sacrificed hundreds of Thanagarian lives.
Enraged that Corsar would try to kill hundreds more to find the full Nth Metal, Katar fought his brother. The battle ended with Corsar being presumed dead and Katar on the run. Corsar survived, though badly burned, and continued to pull the strings of his sister Shayera from behind the scenes. Eventually, when Katar was captured as Hawkman on Earth, Corsar finally revealed himself to his sister. Shayera, however, felt betrayed and ended up damning herself and Corsar to death, allowing Katar to escape.