Complex sentence: When he died his widow married William Huntington S.S., an eccentric and polemical preacher who regarded himself as a prophet, who used his new riches to build a £10,000 chapel.
Split into simpler sentences: When he died his widow married William Huntington S.S., an eccentric and polemical preacher who regarded himself as a prophet. Huntington used his new riches to build a £10,000 chapel.