John Gage wanted his son Thomas to become a Jesuit, and to this end sent him for a schooling with the Jesuits of the College of St. Omer in the Low Countries and seems to have been an unremarkable pupil. From St Omer he was sent for further education with a view to becoming a Jesuit priest to the English College at Valladolid in Spain. Valladolid was the scene of a good deal of rivalry and bad feeling between the different religious orders, a situation worsened by the temperamental and political tensions between the Spanish and the English. Gage developed a contempt for the Jesuits and chose the Dominicans. He joined the Dominicans in Jerez, Spain, taking the religious name Tomás de Santa María, and his pro-Jesuit father disinherited him. He volunteered in 1625 for the mission to the Philippines. Before his departure a royal decree forbade any foreigner, under severe penalties, to go to the Spanish colonies. Fellow friars aided Gage to board the ship for the Indies, and he was hidden in a barrel and the party of thirty or so Dominican friars sailed from Cadiz, on 2 July 1625.