O'Neill was born into a family of eight in the old port city of Belfast, Ireland. He grew up in a working class community where most men went to sea as merchant sailors on deep-sea cargo ships. O'Neill, however, began drawing and painting at an early age. By age ten he was not only an accomplished artist, but also a gifted musician teaching himself four different musical instruments. Today, O'Neill is considered one of Ireland's greatest living landscape painters....
