On 27 November, he affirmed the Fueros of Navarre, which limited his power by putting him under the counsel of a tutor from among the aristocracy.

He received the rites of unction and coronation from Pope Alexander IV in 1257 and 1259 respectively and tried to justify his divine right to rule, a concept foreign until that point in Navarrese politics.

In order to counter the tendency to decentralisation, diminish the power of the nobility, and evade the control of the fueros on him, Theobald turned to the bourgeoisie.

He exacted extraordinary taxes and imposts from them, but they supported him nevertheless because he granted them rights, prestige, and political clout.

Eventually he tried to put an end to the fights between boroughs in 1266, pushing an agreement among the councils of the three Pamplonese boroughs—not that it avoided ultimately the destructive war of the Navarreria in 1276.

Approximately 6.75% of royal revenues were spent on a bureaucracy, 33.84% on the military, and 59.6% to the maintenance of the monarch and his household and duties.