What is the fiduciary duty of a trustee in a personal trust?

The concept of fiduciary duty has its roots in the law of trusts. Its purpose was to ensure that a trustee with control of a beneficiary's property placed the interests of the beneficiary ahead of his or her own interests. While fiduciary obligations have now expanded beyond the law of trusts, the basic principles remain the same. A fiduciary relationship is one in which the fiduciary has the power to make choices which unilaterally affect the interests of a beneficiary and the beneficiary is particularly vulnerable to the fiduciary. See Frame v. Smith, 1987 CanLII 74 (SCC), [1987] 2 S.C.R. 99. It is as a result of this vulnerability, and the corresponding power of the fiduciary, that the fiduciary has a duty of utmost good faith to act in the best interests of the beneficiary and to avoid a conflict of interest.