Complex sentence: On February 16,1918 the Council of Lithuania declared the re-establishment of independence from Russia, basing on nation's self-determination right i.e. Lithuanians were creating state within Ethnic Lithuanian borders.
Split into simpler sentences: On February 16,1918 the Council of Lithuania declared the re-establishment of independence from Russia. This was based upon the right of self-determination, i.e. Lithuanians were creating a state within Ethnic Lithuanian borders.