The historical evolution of express donative trusts in the English Middle Ages down to today both explains and frames the basic elements of a common law trust. Today, trusts in common law countries - and also in many civil law jurisdictions with the exception of China - are utilized in the private donative context to preserve and administer family wealth in ways not otherwise achievable. This paper outlines the basic elements of a common law donative trust from a functional perspective, explaining how trust work as a form of gratuitous transfers and why,