Elinor Costayne

Queen Elinor Costayne was a wife of Maegor Targaryen, one of the three "Black Brides".

History
King Maegor married Elinor out of desperation for an heir, after failing to produce one with his first three wives, choosing her because she was of proven fertility. Her late husband was at some point killed by Maegor. However, she still miscarried just like the others.

In the books
In The World of Ice & Fire and Fire & Blood, Elinor Costayne's husband Theo Bolling was executed, accused of conspiring with Queen Alyssa Velaryon to place Prince Jaehaerys on the Iron Throne. After seven days of mourning, she was forced to marry King Maegor.

After King Maegor's death, Elinor became a septa and Mother of the Great Motherhouse of Lannisport.