Aemon Blackfyre

Aemon Blackfyre 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
Aemon Blackfyre was the second son of Daemon Blackfyre, a legitimized bastard of King Aegon IV Targaryen and his cousin Daena Targaryen, by Serena Blackfyre. He had two brothers: Aegon, his twin, who had been born first, and Daemon II Blackfyre.

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

In the books
In the A Song of Ice and Fire novels, Aemon was Daemon Blackfyre squire along with his brother Aegon.