[2] In circa 1188, Theodore, likely already the ruler of his native Philadelphia, secured the allegiance of the larger part of the city's inhabitants, but also of the surrounding areas of Lydia and the support of the Armenian communities in the Troad.

After some initial skirmishes, Theodore was besieged in Philadelphia (June 1189), but then Isaac learned of the rapid approach of the Holy Roman Emperor, Frederick Barbarossa (r. 1155–1190) who was on his way to take part in the Third Crusade.

[3][4][6] In circa 1193 (or possibly 1190), however, Basil Vatatzes, the doux of the Thracesian theme and megas domestikos of the Byzantine army, forced him to flee to the court of the Seljuk Turks at Iconium.

[3][4] In the chaos of the Fourth Crusade and the eventual fall of Constantinople in 1204, a number of individuals took advantage of the situation to proclaim themselves independent or lay claim to the vacant imperial throne.

[3][4] After securing Philadelphia, he decided to take on Henry of Flanders, one of the Crusader chieftains and future Latin Emperor (r. 1206–1216), who was encamped at Adramyttium and who was attempting to crush the remaining Byzantine resistance in Anatolia.