 He immediately came to an agreement with Grimoald's other son, Romualdo I of Benevento, who pledged loyalty in exchange for recognition of the autonomy of his duchy.Perctarit developed a policy in line with the tradition of his dynasty and supported the Catholic Church against Arianism and the chapters anathematized in the Three-Chapter Controversy.He sought and achieved peace with the Byzantines, who acknowledged Lombard sovereignty over most of Italy, and repressed the rebellion of the Duke of Trent, Alahis, although at the cost of hard territorial concessions to Alahis (including the Duchy of Brescia).