Leo III the Isaurian
Agallianos served as "tourmarches" of the Theme of Hellas in 726/7, when the theme erupted in revolt against Emperor Leo III the Isaurian. Along with Stephen, possibly the commander of the Karabisianoi naval district of the Cyclades, Agallianos became the leader of the revolt, and a certain Kosmas was acclaimed as emperor by the rebels.