Then he came to England on the English Mission, but the excitement caused by Titus Oates's narrative of the Popish Plot meant he returned to France.
Betham then revived an old project for erecting a seminary for the benefit of such of the English clergy taking degrees in the university of Paris.
In 1667, this institution was expanded by Thomas Carre (né Miles Pinkney); but the scheme was not completed until many years later, when Betham was appointed to preside over the seminary.
He was appointed preceptor to the Chevalier de Saint George, and after King James's death that office was confirmed to him by commission, dated 30 October 1701.
[2] Betham was able to purchase a house and garden in the Rue des Postes, Faubourg Saint Marceau, and open St Gregory's seminary by letters patent from the king of France in 1701.