Saint Demetrius of Rostov was a leading opponent of the Caesaropapist reform of the Russian Orthodox church promoted by Feofan Prokopovich. He is representative of the strong Ukrainian influence upon the Russian Orthodox Church at the turn of the 17th and 18th centuries. Danylo Savvich Tuptalo was born into a Cossack's family in 1651 and entered the Kievo-Mohyla Academy at the age of 11. In 1669 he took his vows at St. Wikipedia
The definitive Wikipedia entry for Dimitry Of Rostov. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Dimitry_of_Rostov