How did the Commonwealth affect the language and culture of Lithuanian nobles?

The formation of the Polish-Lithuanian Commonwealth significantly accelerated the cultural and linguistic Polonization of the Lithuanian nobility. While the state maintained a dual structure, the influence of Polish political culture, the Roman Catholic Church, and the aristocracy led the Lithuanian nobility—regardless of their ethnic Lithuanian or Ruthenian origins—to adopt the Polish language and customs.123

By the end of the 17th century, the Lithuanian nobility had become virtually indistinguishable from their Polish counterparts in terms of culture and language. This shift was further solidified when Polish replaced the Ruthenian language as the official medium for legal and administrative purposes in 1697, a change that merely ratified the existing preference for Polish among the upper classes.231

It is important to note that this process of Polonization was largely confined to the nobility and the elite. In contrast, the peasantry remained largely unaffected by these cultural shifts, continuing to speak their traditional languages throughout this period.23