Ethnic Greeks indigenous to the high plateau of Eastern Anatolia to the immediate south of the boundaries of the Empire of Trebizond – essentially the northern portion of the former Ottoman Vilayet of Erzurum between Erzinjan and Kars province, that is the western half of the Armenian Highlands – are sometimes differentiated from both Pontic Greeks proper and Caucasian Greeks. These Greeks pre-date the refugees and migrants who left their homelands in the Pontic Alps and moved onto the Eastern Anatolian plateau after the fall of the Empire of Trebizond in 1461. They were mainly the descendants of Greek farmers, soldiers, state officials and traders, who settled in Erzurum province in the late Roman and Byzantine Empire period.