The defendant maintains that since the original petition had gone to judgment, it was not subject to amendment. See Superior Court Rule 57, 99 N. H. 617. The issue of the pendency of the action was before the Trial Court at the time of the hearing, and it cannot be assumed that the status of the action was ignored. Since the order permitted the amendment, a preliminary order vacating the judgment of dismissal is to be implied. See Chabot v. Shiner, 95 N. H. 252, 255. Such an order was within the authority of the court. Lyford v. Academy, 97 N. H. 167; Bussey v. Bussey, 94 N. H. 328, 329. The defendant was not *28prejudiced, since a new action would not have been barred by limitations had the motion been denied.
The defendant argues that the plaintiffs are barred under the doctrine of res judicata because the issues now raised were decided on the former transfer. Patey v. Peaslee, supra. But there it was expressly stated that the question of whether “ordinary fraud” (Heath v. Heath, 85 N. H. 419, 430), although insufficient to warrant a decree of annulment, might yet justify the imposition of a constructive trust on the property inherited by the defendant was “an issue not presented in this case.” Patey v. Peaslee, supra, 339. The issue previously determined was whether the petition stated a cause for annulment of the marriage. The amended pleadings raise the issue of whether a cause is stated for the imposition of a constructive trust. These issues are distinct, and since the issue now presented has not been. litigated, the doctrine of res judicata does not apply. Laconia Nat. Bank v. Lavallee, 96 N. H. 353, and authorities cited.
The amended allegations charge in substance that, knowing that the decedent was possessed of property of substantial value, and was of unsound mind and suffering from physical disabilities from which she would shortly die, the defendant entered into a marriage with her, intending at her death to marry another woman with whom he had been in communication and whom he in fact married shortly after the death of Winifred. They further charge that in entering into the marriage with Winifred the defendant concealed from her his sole purpose in doing so, which was to become a beneficiary of her estate, and that he thereby committed a fraud upon her and upon the plaintiffs, as her heirs-at-law. We are of the opinion that the amended petition states a cause of action for equitable relief, and that the ruling that it did, which the reserved case states was implied by the action of the Trial Court, should be sustained.
The defendant urges that the relief sought would violate the requirements of the statutes of descent and distribution under which the defendant is entitled to a specified share of the decedent’s estate in the absence of proof that at the time of her death she was justifiably living apart from him because he had been guilty of conduct constituting a cause for divorce. RSA 560:12, 13, 18, 19. The argument disregards the nature of a constructive trust. The plaintiffs do not now seek to prevent inheritance by the defendant but rather to require him to hold for their benefit the property *29which he acquires under the statute. See Colby v. Colby, 96 N. H. 452. The statute will operate to vest title in the defendant. The question of whether he shall be required because of tortious conduct to hold that title for the benefit of the plaintiffs is independent of and unrelated to the statute under which he takes. In the language of one of an analogous class of cases, establishment of a constructive trust will “not interfere with any vested legal rights” but will give effect to equitable rights of others where “the legal title to property was obtained through means or under circumstances which rendered it unconscionable for the holder of legal title to retain and enjoy the beneficial interest.” Vesey v. Vesey, 237 Minn, 295, 301.
The principle upon which the plaintiffs’ claim is founded has long been recognized, and is stated by Pomeroy as follows: “In general, whenever the legal title to property, real or personal, has been obtained through actual fraud . . . concealments, or through . . . taking advantage ... or under . . . circumstances which render it unconscientious for the holder ... to retain and enjoy the beneficial interest, equity impresses a constructive trust ... in favor of the one . . . equitably entitled.” 4 Pomeroy’s Equity Jurisprudence (5th ed.) s. 1053.
The principle rests upon the doctrine that restitution will be compelled to prevent unjust enrichment. As stated in the Restatement of the Law, Restitution, s. 133(1): “A person who has committed a tort against another by obtaining property through fraud, duress or undue influence upon the transferor, thereby knowingly preventing the other from acquiring the property, is under a duty of restitution to the other.” See also, Id., comment a; s. 166, comment d; s. 169, comment c; Morgan v. Morgan, 94 N. H. 116, 119.
Since the transfer to the defendant did not occur during the lifetime of his former wife, it is obvious that no action could have been brought by her to recover it or to prevent the defendant from taking his statutory share as her widower, short of an action for annulment of the marriage, which under the prior decision of this court could not have been maintained. Patey v. Peaslee, supra. The defendant argues that the plaintiffs should not be accorded greater rights than the decedent herself would have had. Her disability to obtain an annulment, like that of the plaintiffs, resulted from the public policy of upholding marriages in the absence of fraud as to matters essential to the marriage relation. *30Heath v. Heath, 85 N. H. 419, 425, 426. Had the transfer been made during her lifetime, however, an action to impose a constructive trust might have been maintained by her. See Miethe v. Miethe, 410 Ill. 226. Since it occurred on her death, the wrong was to the plaintiffs. The fact that it was impossible for the decedent to bring an action during her lifetime affords no reason for denying the plaintiffs a remedy.
The plaintiffs by their amended petition take upon themselves a heavy burden of proof. They must establish by clear and convincing proof (Ibey v. Ibey, 93 N. H. 434, 436; Chabot v. Shiner, supra) the existence of a confidential relationship between the defendant and the decedent in which the defendant occupied a dominant position; and that he used this position, either by concealment of his purpose or by undue influence, to procure the marriage solely to obtain the decedent’s property. Manos v. Papachrist, 199 Md. 257; Miethe v. Miethe, 410 Ill. 226; Small v. Nelson, 137 Me. 178; 3 Bogert, Trusts & Trustees, s. 482. Cf. Stewart v. Hooks, 372 Pa. 542. They must further prove that the decedent was thereafter incompetent to dispose of her property, so that but for the marriage it would have gone to the plaintiffs by intestacy; or if she was competent, that she would have made no other disposition of it. If the plaintiffs succeed in maintaining this burden of proof, the burden of going forward will shift to the defendant, to show that the action by which ho obtained title to the property was fair, and taken in good faith. Manos v. Papachrist, supra; Hollinger Will, 351 Pa. 364; Menary v. Whitney, 244 Iowa 759.
The order upon the present transfer of the case is
Exception overruled.
Wheeler, J., took no part in the decision; Blandin, J., dissented.