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The people behind Keystone Family Advisers

Our people are your keystones
Jonathan Gage portrait

Jonathan Gage ACA FCSI

Jonathan founded Keystone and is a Director of the firm. He has over 22 years of experience of working with wealthy families at firms such as Lloyds, Fleming Family & Partners, UBS Wealth Management and Barclays Wealth, winning awards for excellence. Prior to that he was a commissioned officer in the British Army, a corporate financier at Brown, Shipley & Co. and Hambros Bank, and an auditor at BDO Binder Hamlyn. He is a qualified chartered accountant and a Fellow of the Chartered Institute for Securities and Investment.

His experience of managing, mentoring, team-building, risk management and coaching people through his City career has led him through postings in the UK and overseas, with a focus on overseas and non-domiciled clients alongside individuals,  UK family offices,  entrepreneurs, executives, VIPs and traditional families.

Jonathan is the Managing Trustee at a large family-owned estate, overseeing strategy, operations, performance and governance. He has other trustee and non-executive director roles, including the Bond Street Art Dealer, Deborah Gage (Works of Art) Limited.

Jonathan has served on a number of charitable committees and has been active in raising money for a number of different causes including injured soldiers and special needs children.

He has lived and worked in France, is married with two children, and enjoys skiing, field sports, gardening and art related activities.

Christopher Miller

Christopher Miller FCSI

Christopher has over 20 years experience in finance, including research on a wide range of products, marketing, and fund directorships. He was an analyst at Cazenove both in the UK and in Asia, was head of operations at a London-based investment boutique, where he set up the asset management division, and he was CEO of an award-winning investment consultant, where he advised institutional and family office clients and conducted due diligence. He now specialises in governance and dispute resolution. He also works to support lawyers in investment litigation or family law cases.

He has a BSc in Economics from the University of Buckingham, is a Fellow of the Chartered Institute for Securities and Investment, and is a CEDR qualified commercial mediator.

He is a knowledgeable and keen technologist, and also enjoys country sports, small scale farming and motorbikes. Christopher has lived in France and speaks good French and is married with three children.

Beat the clock

When there are not enough hours in the day, you may need extra support, and you don’t even have time to get people up to speed. That’s where Keystone excels.


Keystone has an almost implausible array of skill sets. That means we can bring together different concerns within the family and see the overall picture.


Technology may be ancillary to family estates and concerns, but it has the power both to obstruct smooth functioning, or solve real life problems elegantly.


We often find that lines of communication can be opened up just by having someone independent to facilitate the dialogue.