delivered the opinion of the court.
This appeal concerns the custody of two male infants born of the marriage of one of the appellants, Jacqualynn A. Shank (hereinafter, the mother), to Ronald Allen Slapnicker. The appeal is addressed to a final order entered June 25,1975, which, in effect, sustained the demurrer filed by appellee Department of Social Services of the City of Virginia Beach (hereinafter, the Department), and we review the facts as they appear from the pleadings.
The natural father died on April 4, 1971. Some time thereafter, the Department, acting upon complaints of child abuse, took the infants into protective custody and placed them in foster homes. Upon appeal from an order entered by the Juvenile and Domestic Relations Court of the City of Virginia Beach, the trial court conducted four evidentiary hearings. By order entered June 19, 1973, the trial court found that “it is for the best interest of [the infants] and for the best interest of the State that such [infants] be separated permanently from [their] sole living parent” and ordered that their “care and custody . .. be committed to [the Department] with the right to place ... for adoption.” This order was never appealed. Before it.was entered, the mother had married appellant Stephen M.vShank, but Shank was not a party to that litigation.
On June 21, 1974, the Department placed the boys for foster care in the Ohio home of their paternal uncle, appellee Gary L. Slapnicker, and his wife, appellee Linda K. Slapnicker (hereinafter, the foster parents). In February 1975, the natural mother made a telephone inquiry concerning the legal status of her sons and was advised that no adoption proceedings had been commenced. On April 17, 1975, with the written consent of the. Department, the foster parents filed a petition for adoption. On June 2, 1975, appellants filed a “Petition and Bill of Complaint” seeking custody of the children, then five and six years of age, and a temporary injunction against adoption by the foster parents pending adjudication of custody; in the alternative, appellants requested “leave to file pleadings and intervene as parties in the matter of the proposed adoption”.
Appellants did not challenge the parental fitness of the foster parents. In support of their prayer for custody, they pled “substantial change of circumstances” affecting the mother’s *508parental fitness. Conceding that the mother was once, during a period of emotional stress, guilty of abusing her children, they alleged that she has since received psychiatric treatment and is now emotionally stable and fit to be a proper parent to infant children. Appellants further alleged that their marriage has been harmonious, that a female child has been born tQ them, that the family enjoys a good standing in the community, and that the family is financially self-sufficient.
Finding from the face of the pleadings that the June 19, 1973 order “is dispositive of the issue of custody”, the trial court denied appellants’ several prayers. No order has been entered on the foster parents’ adoption petition, and they have voluntarily suspended further proceedings pending this appeal.
The crucial question is whether the June 19, 1973 order effectively severed the parental rights of the natural mother. We hold that it did. Our holding controls, related questions, and we affirm.
This order was not “modified or vacated” under Rule 1:1. It was not appealed. It was as final as if affirmed by this Court on appeal and is immune from collateral attack, except upon jurisdictional grounds.
Appellants do not challenge the trial court’s jurisdiction over the parties or over the subject matter. Rather, their position seems to be that the trial court exceeded its jurisdiction insofar as its decree sought to divest the mother of custody permanently. They say that under the common law rule a court “retains the power to decide issues concerning the custody of children throughout their infancy and to affirm, modify or revoke any previous orders or decrees, however valid when entered”.
But, as applied to a parent’s right to custody, as distinguished from other issues concerning custody, the common law rule has been modified by statute. As we noted in Lowe v. Grasty, 203 Va. 168, 172, 122 S.E.2d 867, 870 (1961), until 1960 courts had no statutory authority t.o take a neglected child from its parent and commit its custody to a local board of public welfare or department of social services and grant such agency power to place for adoption. Under Acts, 1960, ch. 331, the General Assembly cured that omission by adding two paragraphs to Code § 16.1-178 which read in pertinent part:
*509“Commitment of a child ... shall not per se confer the right upon the receiving agency to place such child for adoption. If proper studies indicate that it is for the child’s best interest and that of the State that such child be separated permanently from its parent, parents or guardian, the order of commitment shall so state ..., in which event the agency having custody of the child shall be free to make such permanent plans for the child as may otherwise be within the scope of the agency’s authority.” Code § 16.1-178 (Repl. Vol. 1975).
By the same Act, former Code § 63-351 was amended to authorize a board under such circumstances to grant the written consent required by that section.
The 1960 amendments were especially suited to cases of child abuse and neglect. The General Assembly created two distinct remedies fashioned to fit diverse circumstances in such cases. One permits the courts to commit the child to an “agency” but withhold power to place for adoption. When applied, this remedy effects a transitory change in the child’s custodial status and a provisional suspension of the parent’s custodial rights without affecting other parental rights. This remedy is designed for the case of a parent who shows extenuating circumstances and demonstrates his potential for rehabilitation as a fit parent. When the court applies this remedy, the parent may subsequently reacquire custody by showing changed circumstances.
The second remedy, designed for a different case, has different consequences. The courts are empowered to commit an abused or neglected child to an “agency” and “to make such permanent plans for the child as may otherwise be within the scope of the agency’s authority.” Under Code § 63.1-56 (Repl. Vol. 1973), a local board has authority “to place for adoption, and to consent to the adoption . .. when the order of commitment.. . provides for the permanent separation of such child from his parent or parents.” Code § 16.1-178 directs that the order of commitment shall so provide when it appears that permanent separation “is for the child’s best interest and that of the State.”
Unlike the first remedy, which authorizes only a suspension of the custodial rights of a parent, the second remedy authorizes a severance of all parental rights, including the right to place for adoption and the right to consent to adoption. The effect of its application is to render the parent a legal stranger to the child. If *510that effect seems harsh, it must be remembered that the effects of child abuse and neglect are often brutal and sometimes fatal, and in such cases the General Assembly has decided as a matter of public policy that parental rights must yield to the best interest of the child and that of the State.
Our construction of the legislative design is reinforced by an analysis of Code § 63.1-204 (Repl. Vol. 1973). That statute provides that when an agency has custody of a child under a voluntary entrustment agreement in which the parent consents to “permanent separation”, the parents may revoke the agreement and reacquire custody at any time before the child has been placed in the home of adoptive parents or, “upon proof of fraud or duress”, at any time before entry of a final order of adoption. The General Assembly could have made similar provision for cases where the agency holds custody under permanent-separation orders of commitment. Significantly, although the statute expressly refers to such cases, no such provision was made. We conclude that the omission was purposeful. Clearly, the legislature intended that permanent-separation orders entered on competent evidence heard by an impartial judge should have greater finality than extra-judicial agreements which are sometimes executed hastily in times of temporary privation or sudden tragedy and always under great emotional stress. See, e.g., Rocka v. Roanoke Co. Dep’t. of Welfare, 215 Va. 515, 211 S.E.2d 76 (1975).
Here, after four separate hearings, the trial court applied the second remedy. Based upon evidence concerning the nature and extent of the mother’s abuse of her sons, the judge decided that their best interest and that of the State required permanent separation from their mother and committed their custody to the Department with the power to place for adoption. We hold that the effect of his order was to sever all parental rights of the mother. There was, therefore, no predicate for appellants’ prayer for injunction pending adjudication of custody, and the injunction was properly denied.
Appellants petitioned to “intervene as parties in the matter of the proposed adoption”. Under Rule 2:15 a new party admitted “by leave of court [may] assert any claim or defense germane to the subject matter of the suit.” Here a claim of right to adopt did not lie, because the appellants did not have the Department’s written consent. Code § 63.1-225 (Repl. Vol. 1973). *511Nor was any cognizable defense available to appellants. Once the mother became a legal stranger to the children, appellants' only viable defense to the petition to adopt was parental unfitness of the petitioners. Appellants asserted no such defense, and we hold that the trial court did not abuse its discretion in denying their petition to intervene.*
Finding no error below, we affirm the judgment.
Affirmed.