The Palaiologoi ruled Byzantium at its weakest point in history, and the empire underwent significant economical and political decline. Even in this state, the empire, famous for its frequent civil wars, was unable to stay united. In 1320, Emperor Andronikos II Palaiologos attempted to disinherit his grandson Andronikos III Palaiologos, despite the death of Andronikos II's son, heir and co-emperor Michael IX Palaiologos (Andronikos III's father). Andronikos III secured the support of a significant number of the aristocracy and a period of civil war, not ended until 1328, ensued. Although Andronikos III was ultimately victorious and Andronikos II was deposed, the empire was damaged economically and for the first time, foreign states such as Bulgaria and Serbia had appeared as significant regulating factors in imperial dynastic disputes (joining opposite sides of the civil war).