As if they weren't already well-connected enough, the world's two greatest dynasties joined forces yesterday as Europe's Rothschild banking clan bought a stake in the Rockefeller group's wealth and asset management business to gain a foothold in the US. The patriarchs of the two families - 96-year-old David Rockefeller and Jacob Rothschild, 76 - cemented a five-decade acquaintance as the younger man's London-based 2bn RIT Capital investment trust bought a 37 per cent stake in the American's business. In addition to bringing together the two doyens, the deal will considerably expand the vast networks of both families. To give a taste: Lord Rothschild's son, Nat Rothschild, is a well-known entrepreneur with stakes in a range of companies such as Genel, the Kurdistan-focused oil producer ... and Bumi, the Indonesian mining group. He was also linked with George Osborne and Peter Mandelson at a notorious party on an oligarch's yacht off Corfu in 2008. Lord Rothschild's niece Kate is married to Ben Goldsmith, brother of Conservative MP Zac Goldsmith and Jemima Khan and son of the late billionaire business tycoon Sir James Goldsmith. On the Rockefeller side, for starters, David's granddaughter Ariana is a successful fashion designer who married the construction heir Matthew Bucklin in 2010. The Rothschilds bought the stake in Rockefeller from French banking group Socit Gnrale for an undisclosed sum.