Kea was among the islands occupied for several years by the Russians during the Russo-Turkish War of 1768–1774, before they were returned to Ottoman control in the Treaty of Küçük Kaynarca.

[1] He was educated in the Greek Gymnasium established by Grigory Potemkin and attached to the Cadet Corps of Foreign Co-religionists graduating as an engineer.

[3] With the outbreak of the War of the Third Coalition in 1803, Papadopoulos formed a battalion and an artillery command with twelve guns from the garrison of Kamenets, with which he went to Corfu (part of the Russian-dominated Septinsular Republic).

[3] In 1805, he published the Legion's regulations (Ερμηνεία της συνισταμένης Λεγεώνος των Ηπειρωτο-Σουλιωτών και Χιμαρο-Πελοποννησίων, "Explanation of the combined Legion of Epirote-Souliots and Himariot-Peloponnesians"), where he exhorted its readers to remember that they are descendants of the ancient Greeks, to emulate the deeds of the celebrated Pyrrhus and Skanderbeg, and bring new glory to the Greek name.

Taking command of the regiment and all the Greek troops in the Ionian Islands, he successfully countered the threat of Ali Pasha of Ioannina.

He established three legions at the mainland outpost of Parga in 1807, and organized the defences at Lefkada (Santa Maura), threatened by Ali Pasha with attack.

[2] He joined the Russian Army of the Danube during the Russo-Turkish War of 1806–1812, and distinguished himself again in several combats with the Turks, until his death in battle before Shumla on 11 June 1810.