When did the distinct Ukrainian identity emerge ?

by anuarkm

I know they were part of the Kievan Rus, yet they are not Russians, they were also part of the Polish-Lithuanian Commonwealth, yet they are not Polish nor Lithuanian. When did the idea of Ukraine as a people emerge, and how was it different from nearby states like Russia?

OmniRed

While not a direct answer, there is adjancent and possibly interesting information in a reply to a similiar question by u/DanyloHalytskyi here.