Question: Who was the leader of the group of five prominent 19th century composers that Alexander Borodin was a part of?
Sentence (from "The Mighty Handful"): Mily Balakirev (the leader), César Cui, Modest Mussorgsky, Nikolai Rimsky-Korsakov and Alexander Borodin all lived in Saint Petersburg, and collaborated from 1856 to 1870.
Relevant evidence: Yes