Complex sentence: He was one of the leading musicians in the Irish capital from 1764 to 1781, when he returned to London; after two years, he came back to Dublin, where he spent the remainder of his life.
Split into simpler sentences: He was one of the leading musicians in the Irish capital from 1764 to 1781, when he returned to London. After two years he came back to Dublin, where he spent the remainder of his life.