Yanka Kupala (Janka Kupała, ; - June 28, 1942) - penname of Ivan Lutsevich was a famous Belarusian poet and writer. Arguably the most famous Belarusian nationalist, Kupala promoted the dying Belarusian language and attempted to further shield it against russification. Currently there is a museum founded by his wife in Minsk which has many examples of his life’s work. Wikipedia
The definitive Wikipedia entry for Yanka Kupala. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Yanka_Kupala