Question: During periods of time, this acquistion or imposition of elements of Polish culture, such as the language, under populations of territories controlled, or under the influence of Poland; Jan Kazimierz Chodkiewicz, a Lithuanian nobleman, is a prime example of this act - what is it called? 
Sentence (from "Polonization"): As with other examples of cultural assimilation, it could either be voluntary or forced and is most visible in the case of territories where the Polish language or culture were dominant or where their adoption could result in increased prestige or social status, as was the case of the nobility of Ruthenia and Lithuania.
Relevant evidence: No