When Captain Harry Wales marries Meghan Markle, it will create a unique transatlantic alliance: the first union between an English prince and an American actress.

Another transatlantic first has taken place in the law in recent weeks, with the announcement of new co-heads at 3 Hare Court – Simon Davenport QC and Jeffrey Golden. One is an English Queen's Counsel, the other an American lawyer and a former partner of Allen & Overy (A&O).

"No one has come to such a role before at the English Bar because they were, or despite the fact that they were, an American lawyer," says Golden.

This is not the first time that he has made a big splash. Having trained at Cravath Swaine & Moore in New York, Golden then transferred to the firm's London office. After 16 years with Cravath, he was appointed as the first US-qualified partner at A&O in 1994. At the time, this move to a magic circle firm was groundbreaking – the first of its kind, and expected to herald a rash of comparable hires, although it took several years before the pace of English and US law firms competing directly in each other's backyards really took off.

"Today, firms like A&O count more non-English than English-qualified partners," says Golden. It cuts both ways: there are more than 6,000 lawyers among the 80-plus US law firms in London, billing more than $5bn a year between them. But Golden is also unique for another reason: he is the first person to head an English set of barristers' chambers who is not himself a barrister.

"In my career, I've been lucky enough to be at right places at right times: we think it's pretty groundbreaking and being entrusted with the responsibility is a privilege," he says. "We can't disappoint people at 3 Hare Court because they think that they're taking it to a place that nobody else has. They deserve credit for being brave, excited and enthused about heading down the path less well travelled by."

Golden's London links have a long history. Although he qualified as lawyer in the US, he also studied at the LSE, where he met his future English wife (in the library), and more recently, became an honorary fellow and a governor. "When I arrived it was still shillings and pennies, and the City of London was full of bowler hats. I'm now co-head of a forward-looking set and surrounded by talent."

Among the lessons he learned at Cravath and at A&O was "the importance that you should attach to recruitment: no shortcuts", adding: "I view recruitment in the same way that some people view buttering toast: if you get the corners right, the rest of it will take care of itself."

An unambiguous anglophile, Golden joined Hare Court in 2014 as a specialist arbitrator, mediator and expert in a wide range of capital markets matters, including swaps and derivatives, international equity and debt offerings, US private placements and listings. He has acted extensively for the International Swaps and Derivatives Association (ISDA) and was a principal author of ISDA's master agreements.

Of the more than 180 sets of chambers in London, some 30-plus have joint heads. 'It's becoming the new norm, particularly as chambers get bigger," says Golden. It was Davenport's idea that the two team up to offer chambers the double benefit of joint heads. Together they are open to expanding from its current base of 37 barristers by increasing the number of tenancies, and by inviting select individuals to join chambers.

"We certainly hope that expansion of our professional opportunities will come from strengthening existing ties that we have with leading City law firms, but also through building on our international network," Golden says.

Both men identify international work as a common thread that runs through the practices of 3 Hare Court barristers. On being an American head of chambers in a distinctly English setting, he suggests: "The hybrid can be a lot stronger than its roots."

So what makes a good head of chambers? "Trying to get the best out of what are already excellent people, channelling their creativity to maximise each opportunity, and effectively allowing them to shine," says Davenport. "We're here to clear the weeds from the undergrowth so that the flowers can shine through."

Golden adds: "Putting chambers ahead of self is an important part of that equation. Bringing others along, realising the potential that chambers represents collectively and the members individually. It's also involves setting a good example."

The new co-heads see their role as "very hands on". In practice, says Davenport, that means "fronting up decisions that need to be made and making them with considered thought, but swiftly".

In synthesising their different strengths and backgrounds, Davenport suggests: "Barristers ultimately have to look out for their own interest. In Jeff, we have someone with the experience of creating teams of people and creating opportunities for an entity as opposed to just for themselves.

"The problem that besets every chambers is that when a busy barrister becomes head, and he or she is trying to keep his or her practice going, trying to fit in being a head of chambers as best as he or she can produces mixed results. In Jeff, we have somebody who has built teams at the highest possible level internationally, doing the best work that's available – we've got it at the head of our chambers. In the 600 years that barristers' chambers have been operating, there's never been a moment like this."

In setting out a vision for the future, Golden adds: "We don't fear new ideas; we do fear some of the old ideas. These are revolutionary times for the legal profession: alternative business structures, the globalisation of English law, which has distinguished itself in so many ways. The English Bar will have many challenges being posed post-Brexit, including from recently announced 'pop-up' courts in Europe which clearly aim to remove business from here to elsewhere.

"Those are challenges which beg creative, if not revolutionary, answers. Rather than waiting for a roadmap or someone else to tell us what that answer is, we're excited about trying to craft those answers ourselves."