Complex sentence: Gregorson Campbell's health deteriorated in the last years of his life especially after the death of his mother Helen at the Tiree manse in 1890; he died on 22 November 1891 before seeing the final printed edition of "The Fians".
Split into simpler sentences: Gregorson Campbell's health deteriorated in the last years of his life especially after Helen, his mother, died at the Tiree manse in 1890. He died on 22 November 1891 before seeing the final printed edition of "The Fians".