The oath taken by British sovereigns at their coronations is laid down by a statute dating from 1688. Any oath taken other than in accordance with the correct statutory form is contrary to law. Taking the authorised form of the oath is a condition on which the crown is held by any individual. The oath taken by the present sovereign omitted the promise to govern according to the statutes agreed upon in Parliament. Any variance from the statutory form is problematic but the clause omitted is the clause that most clearly expresses the central concern of the Williamite settlement. The deficiencies in the oath taken, while reasonably apparent, do not appear to have been judicially recognised hitherto. The legal basis of the present oath has been raised in the political sphere but potential difficulties have been set aside on grounds of expediency. Given the unlawfulness of the oath taken, there is a political and constitutional imperative in establishing that deficiencies in the oath do not fatally taint the reign which follows. This article will advance two possible legal means of reconciling an improper oath with a perfectly valid reign.