[1][2] The first waves of Russian settlers onto what became Ukrainian territory came in the late 16th century to the area known as Slobozhanschyna or Sloboda Ukraina, in what is now northeastern Ukraine.
[3] More Russian speakers appeared in the northern, central and eastern territories that are now Ukraine during the late 17th century, following the Cossack Rebellion (1648–1657) which Bohdan Khmelnytsky led against Poland.
This brought significant, but still small, wave of Russian settlers into what is now central Ukraine (primarily several thousand soldiers stationed in garrisons,[3] out of a population of approximately 1.2 million[4] non-Russians).
At the beginning of the 20th century, Russians were the largest ethnic group in almost all large cities within Ukraine's modern borders, including the following: Kiev (54.2%), Kharkiv (63.1%), Odessa (49.09%), Mykolaiv (66.33%), Mariupol (63.22%), Luhansk, (68.16%), Kherson (47.21%), Melitopol (42.8%), Yekaterinoslav (current Dnipro), (41.78%), Yelisavetgrad (current Kropyvnytskyi) (34.64%), Simferopol (45.64%), Yalta (66.17%), Kerch (57.8%), Sevastopol (63.46%).
With the gradual urbanization of Society in the late 19th century, Ukrainian migrants from rural areas who settled in the cities entered a Russian-speaking milieu.