Royal London's chief executive Phil Loney will stand down by the end of 2019.
Mr Loney is leaving to concentrate on his longstanding charitable interests in the international development sector and supporting people with learning difficulties.
The news was revealed today (December 11) at the same time that Royal London announced chairman, Rupert Pennant-Rea, will leave his post at the end of 2018.
He will be replaced by Kevin Parry, a senior independent director at Standard Life Aberdeen and chairman of Intermediate Capital Group, the asset manager.
Mr Loney said: "It has been an incredible privilege to lead Royal London over the last seven years and to work with so many dedicated and professional colleagues.
"Growing this business has been a real team effort with all credit to my executive team and their people.
"I am particularly proud that, as a member-owned business, our customers are centre-stage and we are able to reward them by sharing our profits.
"I have no doubt that Royal London will continue to go from strength to strength and I wish all of our people continued success in years to come."
Since joining Royal London in 2011, Mr Loney has overseen 154 per cent growth in the UK's largest life, pensions and investment mutual from £46bn assets under management to £117bn at the end of June 2018.
Total life and pension new business sales for Royal London have quadrupled from under £3bn in 2011 to more than £12bn in 2017, creating a business that is a top four new business player in its key sectors.
Mr Loney has also led the transformation of Royal London from a collection of individual brands into a single brand.
Al Rush, principal at Rutland-based Echelon Wealthcare, said Mr Loney stepped forward to offer financial assistance for British Steel pension scheme members when the problem flared up at Port Talbot.
Mr Rush said: "He did so discretely and without qualification so his next move doesn’t surprise me in the slightest.
"He was also immeasurably generous and supportive when I launched the first Pension Debate in Peterborough, as well as starring the brand transition to Royal London from Scottish Life.
"I think Royal London will look back at this period as a corporate golden age."
Mr Pennant-Rea, chairman of Royal London, said: "On behalf of the board I would like to thank Phil for his dedication to and success in transforming the scale, reach and visibility of Royal London.
"He leaves the business both in a significantly stronger position than when he joined and extremely well-positioned for continued future success."
Mr Parry, who will lead the search for a new chief executive, said: "I am honoured to have been selected as chairman of Royal London.
"I am firmly committed to the principle of mutuality and am looking forward to working with the rest of the board, executive team and a new chief executive to take Royal London on the next phase of its growth."