What's at the core of the Joan Fontaine/Olivia de Havilland feud?

Olivia never wanted a sibling and was favorited by their mother because of Joan’s health in childhood. After Olivia started to land roles she supported the family which made their mother pay more attention to Olivia. When Joan wanted to start acting the family forbid her from using their last name. They didn’t want her bringing down the family name so she chose their hated stepfathers last name. Eventually Joan started acting and gain bigger success faster than Olivia which riled up old rivalries. When Joan one an Oscar before Olivia she finally felt superior and snubbed Olivia’s congratulation. When Olivia one gets she did the same thing to Joan which further separated them. Joan talked shit about Olivia’s husband which made them not talk for years. Eventually what made them lose total contact was when their mother got sick and they disagreed on a treatment. They never talked again and Joan died in 2013 leaving a remorseful Olivia. Hope I explain well enough.

I think Fontaine is a nice name.

And so is De Havilland. It soars.

Joan is funny and interesting in interviews. There's a few on YouTube. She says much of what R1 posted. Olivia seems kind of off/odd in this clip with Bette. Sort of wired. Both Joan and Liv have beautiful voices, Not entirely British or American, Mid Atlantic movie star from Hollywood's golden age.