In the same year he granted Aosta Valley the "Charte des Franchises", recognising the right to administrative and political autonomy (this right was maintained until the French Revolution).

In part, this was done by getting many of his sons into episcopal offices in surrounding territories, at a time when bishops had temporal as well as spiritual authority.

[3] In addition to William and Boniface, who made their careers in the clergy, their brother Thomas started out as a canon at Lausanne and became prévôt of Valence by 1226.

This established a close relationship between the two adjoining counties which would help cement Savoy's control over trade between Italy and France.

[9] Thomas also made a policy of granting franchises and charters to towns on key trade routes, which enabled the merchant class to develop more wealth and built support for his rule.