Complex sentence: Its namesake is St. Vincent de Paul, a sixteenth-century French monk, founder and patron of the Sisters of Charity, an order of Roman Catholic nuns that focuses on care for the poor, best known for their idiosyncratic "Flying Nun" habits.
Split into simpler sentences: Its namesake is St. Vincent de Paul, a sixteenth-century French monk. He founded the Sisters of Charity, an order of Roman Catholic nuns that focuses on care for the poor, best known for their idiosyncratic "Flying Nun" habits.