|Died||In 47 AC|
|Spouse||Lady Elinor Costayne|
The World of Ice & Fire (mentioned)|
Fire and Blood (mentioned)
Theo was a landed knight during the reign of King Maegor I Targaryen. He was married to Elinor Costayne, with who he had three sons. Ser Theo participated in one of King Maegor I's campaigns against the Poor Fellows. In 47 AC, Theo was arrested by knights of the Kingsguard and accused of conspiring with Dowager Queen Alyssa Velaryon to place Prince Jaehaerys Targaryen on the throne. Although he declared his innocence, Theo was found guilty and beheaded that same day.
Seven days after Theo's execution, King Maegor I announced that he would wed Theo's widow, Lady Elinor. After the wedding, Maegor dispatched one of Theo's sons to be fostered at the Eyrie by House Arryn and the other at Highgarden by Lord Tyrell, while the youngest was given to a wetnurse.