Daemon I Blackfyre

Daemon Blackfyre, born Daemon Rivers is an unseen character in Game of Thrones. He is not expected to appear in the series, being long dead by the time it begins.

Background
Daemon Blackfyre was the legitimized bastard son of King Aegon IV Targaryen.

Season 1
Daemon, along with his bastard siblings is mentioned in the House Targaryen's entry of the book The Lineage and Histories of the Great Houses of the Seven Kingdoms