Complex sentence: He converted to Catholicism, and they had three children, but he only saw her twice after 1850, and she would relocate to France with their children in 1853, and died there in 1860.
Split into simpler sentences: He converted to Catholicism, and they had three children. However, he only saw her twice after 1850, and she would relocate to France with their children in 1853, and died there in 1860.