الإمبراطورية اللاتينية
The accession of Vatatzes was initially challenged by the Laskarids, with the "sebastokratores" Isaac and Alexios, brothers of Theodore I, seeking the aid of the Latin Empire. Vatatzes prevailed over their combined forces, however, in the Battle of Poimanenon, securing his throne and regaining almost all of the Asian territories held by the Latin Empire in the process.