Unlike the thoroughly Hellenized areas of the western and central Black Sea coast and the Pontic Alps, the Erzinjan and Erzerum regions were primarily Turkish- and Armenian-speaking, with Greeks forming only a small minority of the population. The Greeks of this region were consequently more exposed to Turkish and Armenian cultural influences than those of Pontus proper, and also more likely to have a strong command of the Turkish language, particular since the areas they inhabited had also been part of the Seljuk Sultanate of Rum and other pre-Ottoman Turkish powers in Central and Eastern Anatolia. Many are also known to have "turned Turk" in both the Seljuk and Ottoman periods, and consequently to have assimilated into Turkish society or reverted to Christian Orthodoxy in the 19th century. Erzurum province was invaded and occupied by the Russian Empire several times in the 19th and early 20th centuries, and large numbers of Eastern Anatolia Greeks are known to have collaborated with the Russians in these campaigns, particularly that of the 1828–29 Russo-Turkish War, alongside Pontic Greeks inhabiting areas to the immediate north of Erzinjan and Erzurum.