Being part of the billionaires' club doesn't mean you have to be friends with your fellow members...

From the proposed cage fight between business rivals Elon Musk and Mark Zuckerberg to the spat between super-rich celebrities Kim Kardashian and Taylor Swift, which recently inspired a thinly veiled "diss track", grab your popcorn and read on for 10 of the most jaw-dropping billionaire feuds of all time. 

All dollar amounts in US dollars.