The Empire of Trebizond was formed after Georgian expedition in Chaldia, commanded by Alexios Komnenos a few weeks before the sack of Constantinople. Located at the far northeastern corner of Anatolia, it was the longest surviving of the Byzantine successor states. Byzantine authors, such as Pachymeres, and to some extent Trapezuntines such as Lazaropoulos and Bessarion, regarded the Trebizond Empire as being no more than a Lazian border state. Thus from the point of view of the Byzantine writers connected with the Lascaris and later with the Palaiologos, the rulers of Trebizond were not emperors.