Serena Blackfyre

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

Background
Serena Blackfyre was wife of Daemon Blackfyre, legitimzed bastard son of King Aegon IV Targaryen and his cousin, Daena Targaryen. She was the mother of the twins Aegon and Aemon Blackfyre, and Daemon II Blackfyre.

Season 1
Serena, along with his bastard siblings is mentioned in the House Targaryen's entry of the book The Lineages and Histories of the Great Houses of the Seven Kingdoms. The tome mentions that he rose in rebellion against his half-brother but perished from wounds sustained at the Battle of Redgrass Field.

In the books
In the A Song of Ice and Fire novels there's no mention of a Serena Blackfyre or of Daemon Blackfyre's wife. It is unknown if Daemon married a bastard daughter of Aegon IV or a woman unrelated to him.