This report into the governance and financial management of endowed charitable foundations -- charities that fund their activities mostly from investments -- is the first research of its kind into this sector. It examines the common principles for the management of charitable foundations and, through interviews and case studies, shows the ways different organisations have implemented them to get the best value for their charitable aims. The report identifies that there are 900 endowed foundations in England and Wales with income over £500k. With collective assets of £48.5bn -- nearly half the Voluntary Sector assets of the UK as a whole - they are together responsible for £2.3bn charitable spending each year