The special relationship bet-ween siblings has sustained many famous partnerships, from chocolatiers Richard and George Cadbury in the Victorian era to serial technology company founders Oliver, Marc and Alexander Samwer in the 21st century.

In other cases, siblings have played the role of saviour, such as Donatella and Santo Versace, who stepped in to run the Italian fashion label after the murder of their brother, and company founder, Gianni in 1997.

However, sibling disputes are also as old as Cain and Abel’s fatal falling out in the Old Testament and the words “sibling” and “rivalry” are regularly conjoined. Moreover, as Jonathan Ortmans at the Kauffman Foundation, which researches entrepreneurship, notes there is less of a stigma nowadays about changing the core team of a start-up. This militates against siblings, he says, because the backers usually want to bring in non-family members.