Complex sentence: Pre-deceased by his wife, Mary Baillie, Cosmo Gordon died without issue in 1800 and was succeeded by his brother Charles, described by architectural historian H. Gordon Slade as "eccentric and excessively penurious".
Split into simpler sentences: Pre-deceased by his wife, Mary Baillie, Gordon died without issue in 1800. Charles was described by architectural historian H. Gordon Slade as "eccentric and excessively penurious".