The major changes for the Belarusian people didn't begin until the Russians took control. During earlier rulers taxes, power, and politics changed, but Belarusian culture and lifestyle remained fairly stable. However, the Russians changed the culture to a great degree as their similarities, including linguistic similarities, led to better communication between the groups and hence great influence from one culture to the next.
Russian control led to cultural changes, but also to a greater Belarusian identity. This ended when the Soviets took over and began to destroy the culture of the Belarusians. The Russian language was forced on the people as religion was destroyed and the people were forced to urbanize as jobs moved from agriculture to industry in large numbers. Although religion has since returned, as have other aspects of the culture, today many Belarusians only speak Russian and the urban lifestyle has become popular and the only place to find jobs in significant numbers.
Today the Belarusians are still changing their culture, lifestyle, and identity. Due to the Soviet past and close ties to Russia today there are still many shared cultural similarities to this past culture and the current Russian people. However, the people are again seeking to re-define themselves as their path forward is uncertain and the cultural battles are ever-present.