Complex sentence: This provided him with a comfortable income for some years, but some unforseen and unknown disaster meant that by the time of his death in 1913 he was living alone in Ealing, West London.
Split into simpler sentences: This provided him with a comfortable income for some years. Some unforseen, and unknown, disaster meant that by the time of his death in 1913 he was living alone in Ealing, West London.