Evelyn de Rothschild, who helped unite the British and French arms of his family’s famous banking group and counted Queen Elizabeth II among those who sought his financial advice, has died. He was 91.

He died “peacefully at home,” the U.K.’s Press Association reported, citing a statement from his family.

Starting in 1976, Rothschild served 27 years as chairman of N.M. Rothschild & Sons, the London branch of the financial dynasty started by his great-great-great grandfather in the late 18th century. Among its many other roles, the bank known today as Rothschild & Co. helped finance the Duke of Wellington’s victory over Napoleon in 1815 at the battle of Waterloo.

Before stepping down in 2003, he achieved a long-planned goal of bringing together the London business with its French counterpart, Rothschild & Compagnie Banque. That was seen as a key step in remaining competitive with much younger – but also bigger – multinational banks.

“The first important strength of the family is unity,” he told the New York Times in 1996, as he and his cousin, David de Rothschild, head of the French house, announced their new partnership.

From 1972 to 1989 he was chairman of the Economist magazine, which, in a 2002 interview with Bloomberg News, he called “probably the most independent publication in the world.”

The Rothschild firm was founded by Mayer Amschel, who started out buying and selling old coins in a Frankfurt ghetto. He took the family surname from the red shield – “rote Schild” in German – that was displayed above an ancestor’s house in the 1560s.

In the early 1800s, he sent his five sons to establish bases of Rothschild in London, Paris, Naples, Vienna and Frankfurt. London-based N.M. Rothschild carries the name of Nathan Mayer Rothschild, Evelyn’s great-great grandfather.

The family’s influence waned in the 20th century because European governments relied on American banks to finance both world wars against Germany. After World War II, Evelyn and his cousin Jacob refashioned N.M. Rothschild as a British merchant bank, which arranged international bond deals for such countries as Chile and Hungary.

The pair had a highly publicized split in 1980 over Jacob’s push to merge with S.G. Warburg & Co., in the hopes of expanding internationally and competing with Wall Street firms. When Evelyn refused, Jacob quit and founded an offshoot investment vehicle, RIT Capital Partners.

“The preservation of family control took precedence over expansion,” British historian Niall Ferguson wrote in his second volume on the Rothschild clan. “It was a serious rift within the English branch of the family.”

For his part, Evelyn Rothschild rebuilt N.M. Rothschild by hiring a series of well-connected bankers. One of them was Michael Richardson, a partner at Cazenove. His friendship with Margaret Thatcher — British prime minister from 1979 to 1990 – helped the bank win the job of lead underwriter in the sales of shares in state-owned companies such as British Gas and British Petroleum.

Rothschild also helped the firm expand in China, where it opened an office in Beijing in 1999.

He was knighted in 1989 by Queen Elizabeth II. He was for many years one of the queen’s financial advisers.

“No one is tighter at spending than the queen,” he told the London Evening Standard in 2017. “She grew up during the war. Very disciplined.”

Evelyn Robert Adrian de Rothschild was born on Aug. 29, 1931, the only son of Anthony Gustav de Rothschild and the former Yvonne Cahen d’Anvers, according to the website of the Rothschild Archive, an independent charitable trust.

Evacuated to the relative safety of the U.S. during World War II, he worked the soda fountain at a drugstore in Westhampton on New York’s Long Island, he told the Financial Times for a 2017 profile.

He returned to the U.K. to be educated first at Harrow School in London, then at Cambridge University’s Trinity College.

He joined his family’s bank in 1957. He was part of its expansion into media and telecommunications, joining the boards of Beaverbrook Newspapers, the Economist and the Telegraph, Ferguson wrote.

In the 2002 interview with Bloomberg News, Rothschild said of his job, “Every day something new pops up out of the woodwork and someone asks me if I can help. I don’t pretend to be a nuts and bolts person. I know quite a lot about certain things, but I’m not a lawyer, I’m not an engineer, I’m not an accountant. But that doesn’t stop you from using your common sense.”

An art collector, wine connoisseur and owner of thoroughbred racehorses who counted Bill and Hillary Clinton among his friends, Rothschild shuttled for many years between London and Ascott House, a country estate in Buckinghamshire acquired by his grandfather in 1876 and decorated with porcelain from Asia and paintings by old masters such as Rubens.

Rothschild’s first marriage, to Jeannette Ellen Dorothy Bishop, ended in divorce. With his second wife, Victoria Lou Schott, he had three children: Jessica, Anthony and David. That marriage also ended in divorce. In 2000, Rothschild married U.S.-born Lynn Forester, co-founder of the telephone network company FirstMark Communications Europe.