Between the fall of the Empire of Trebizond to the Ottomans in 1461 and the Russian annexation of Georgia in 1801 there had been several waves of Pontic Greeks who left the eastern Black Sea coastline and the highlands of the Pontic Alps and then settled as refugees or economic migrants in Georgia and the South Caucasus. The largest and most recent waves came in the late 18th and especially the early 19th century, when the South Caucasus experienced mass migrations of Greeks from the Ottoman Empire, mainly from the region of Pontus as well as the vilayets of Sivas and Erzurum in northeastern Anatolia. This wave of Pontic emigrants is particularly associated with the 1828-29 Russo-Turkish War, when many Pontic Greeks collaborated with or welcomed the Russian army that had occupied the region and then, to escape likely Turkish reprisals, followed it with their families when it withdrew back into Russian territory.