In 1831, Ioannis Kapodistrias became governor of Greece. Kapodistrias quarreled with the Mavromichalis clan because the Maniots refused to pay taxes to the new government. Kapodistrias requested that Tzanis, Petros' brother, go to Nafplio, then capital of Greece, and negotiate. As soon as Tzanis arrived, he was arrested and imprisoned. Kapodistrias then sent soldiers to Mani and had Petros arrested, imprisoned, and charged with high treason. His brother Konstantinos, the defender of Nafplio, and Petros' son, Georgios Mavromichalis, were put under house arrest in the capital.