"If I had been sitting here last year and you'd asked me about growth plans, I wouldn't have been able to predict what happened."

Goodwin Procter London co-head Paul Lyons is reflecting on the rapid expansion the US firm has made in London and Europe during the past 12 months. In hindsight, the hire of former King & Wood Mallesons (KWM) corporate co-head Richard Lever in 2015 has proved hugely beneficial, with a number of Lever's former KWM colleagues subsequently joining him at the US firm.

These have included a lucrative six-partner Paris private equity team in April 2016, followed by a five-partner London team led by UK investments funds head Michael Halford six months later.

Fellow London co-head Samantha Lake Coghlan says: "With Richard starting to build the private equity transactional side of the business, we refocused our efforts to grow our private equity funds team. When the KWM funds team wanted to move, that allowed us to bring that piece in."

Lyons adds: "Richard knew those guys really well, and knew they would tick all the boxes."

While the break-up of KWM's European arm has proved serendipitous for Goodwin, Lake Coghlan – who joined from Ashurst in 2012 alongside fellow real estate funds partner and now European chair David Evans – says the intention was always to build in private equity as well as real estate.

She says: "Before you join something that has nothing in London, you want to know what the plan is. It became apparent it would be easier to build real estate first as David and I were both real estate lawyers, and the market was buoyant then. We've now built up top to bottom and side to side in real estate and private equity."

The London office now has 125 staff, including more than 70 lawyers. Including the addition of the 26-strong KWM team earlier this year, the firm has now recruited a total of 113 lawyers – including 26 partners – in Europe during the past two years. In London, it has added 51 lawyers, including 11 partners, in the same timeframe.

Embedding these new capabilities is now at the top of the firm's agenda. Integration is described by Lyons and Lake Coghlan as the firm's "number one play", and was the theme of Goodwin's recent partner retreat in Boston.

To encourage partners to get to know each other, the firm laid on a 'speed dating'-style initiative, where partners were assigned to sit opposite a partner from a different practice area and office and spend time talking about their work. Each office brought a gift – English partners brought shortbread, while German partners brought beer.

The pair are proud of these efforts, and stress the need for new recruits to integrate well. Lyons says: "You're not going to just be measured how you personally have done after one or three years – it's about how well have you integrated into the team, and how often you bring opportunities to them. Has the team grown as a result of your hire? The firm lives or dies by that premise. If you pick the right people, they will do that."

Further growth is now on the cards, with the firm looking to its US capabilities to guide its next stage of growth. It has pinpointed its tech, life sciences and financial institutions groups as areas to build in London and Europe.

Lyons adds: "We've always had a desire, where sensible, to build out and emulate the practice areas we have in the US in London and Europe. Given the strength of our tech, life sciences and financial institutions groups in the US, it would be a bit daft of us to not work out what the opportunities are to leverage those in the European markets."

The firm is also looking to expand its European-based support staff function to service those offices that have already seen growth.

Goodwin has also decided to expand its City trainee intake after launching the offering earlier this year, when it took on five from KWM in January. The US firm is set to take on three City trainees this September, and will continue to do so on an annual basis.

As UK firms assess how best to break into the largest legal market in the world, the London heads recognise the office's strength lies in how it links up with the "mothership".

Lake Coghlan says: "The need to have a strong US side of the business is crucial. It's a global world nowadays, and if you don't have a strong US arm you're just not as competitive and you're not servicing your clients in the same way. Our clients are global clients – the benefit of being able to serve them on both sides of the Atlantic is necessary. We'd be missing opportunities if we weren't doing that."

With London management determinedly directing energies towards new areas of expansion after a year of successful growth, opportunities are expected to continue to arise. As Lyons puts it: "If something makes sense from a business perspective, we'll do everything we can to bring it home."