He served as a captain in the papal army in Rome until his death in battle in 1551, which ended the male line of the Arianiti family in Italy.
Following in the footsteps of his father Gjergj Arianiti, who had fought the Ottomans during their invasion of Albania, Constantine had sought to establish himself as a leadership figure among the Balkan refugees in Italy.
[8][5] Arianitto lived with his mother for a time in the mountain village of Montefiore Conca, where Constantine had spent his last few years, though the two later moved to Rome.
In Rome, Arianitto joined the papal military, rising through the ranks until he was eventually made captain of a contingent of soldiers.
Arianitto was killed in battle on 16 November 1551 at Torchiara during a conflict between Pope Julius III (r. 1550–1555) and Ottavio Farnese, Duke of Parma (r. 1547–1586).