When the Greek War of Independence broke out, Theodoros and his brother Yiannoulas, who was the successor in the leadership of "Ziakas' Armatoliki", begun the war to the Ottomans and liberated the region of Grevena.

In 1826 Mehmet Agha leader of Ottoman military troops attacked and destroyed the headquarters of "Ziakas' Armatoliki" in Grevena.

Yannulas Ziakas was killed in that battle, but Theodoros got away in Southern Greece.

However, under pressure from the large Ottoman army and the unpropitious diplomatic circumstances, a truce was negotiated by the consuls of Britain and France.

Hostilities ceased in June 1854 and the rebel leaders returned to the Kingdom of Greece.