Theodonem's early life is not very shown. He lost his mother very young, as well as his father, when he was only four years old. Raised by Maethoriel, he learned how to speak Quenyan and Sindarin, how to behave in front of the court and how to fight. He took the whole power of Rohan at the age of twenty, in TA 307, after fourteen years whithout having any access to the throne due to his young age.