To quote the listing,
This brand new and exclusive three-part series delves into the relationships of six prominent women from world history – sisters by birth, all enjoying very different relationships with each other. The series explores the fascinating but sometimes fractious lives of aviation hero Amelia Earhart, Jackie Kennedy Onassis, and the infamous Mitford sisters.
I’m especially keen to watch the third instalment when I’ll be able to learn more about Lee Radziwill, sister of the late Jacqueline Kennedy Onassis. She was married in 1959 to Stanislaw Radziwill (1914 – 1976).
It seemed evident that Stanislaw and Constantin were from the same family, but what exactly was the connection? I set myself the task of finding the link. Using a number of sources online, including Wikipedia, geni.com, and thepeerage.com, I finally had to reach back as far as the 16th century to discover that both men were indeed descended from a common ancestor – Aleksander Ludwik Radziwill (1594 – 1654).