You have requested our opinion as to whether the deceased number holder's first wife
                  is estopped from denying the validity of her divorce from the number holder. Additional
                  questions raised in this claim are whether, if the principle of estoppel applies,
                  the second wife should be considered the legal widow of the number holder, and whether
                  the first wife should be considered to be the surviving divorced spouse even though
                  there is no final divorce decree.
               
               The facts as contained in the file are that Bonnie M~ and Ronald W~ were married in
                  Winterhaven, California, on August 8, 1964. In May 1968, Bonnie filed for a divorce,
                  and the Superior Court of California for the County of Los Angeles, entered an Interlocutory
                  Judgment of Divorce. The interlocutory Judgment of Divorce contained a cautionary
                  notice, "This is not a judgment of divorce .... The final judgment of divorce will
                  not be entered unless requested by one of the parties." A July 25, 1980, report of
                  contact with the Los Angeles County Court House, indicated that a search of the divorce
                  records had revealed that no final decree of divorce was filed.
               
               Bonnie M~ married Ronald A~ on February 1, 1970. On petition of Ronald A~, the Superior
                  Court of California granted an annulment of this marriage pursuant to California'
                  Code Section 4401, finding the marriage bigamous and void. The final judgment of nullity
                  was entered on July 7, 1971.
               
               Mary V~ ceremonially married Ronald W~ on May 10, 1969 in the State of Indiana. The
                  number holder died on March 12, 1980, while he was domiciled in the State of Kentucky.
                  Mary W~ stated that she believed the number holder was free to marry at the time of
                  their wedding ceremony.
               
               In a May 14, 1980, Report of Contact, Mary W~ stated that she and Ronald had talked
                  to Bonnie on the phone and that Bonnie was aware of their marriage. Bonnie reported
                  that in the course of the same telephone conversation she told the number holder that
                  his marriage was invalid because there was no divorce. At one point in the file, in
                  the May 14, 1980, Report of Contact, the district office representative stated, "My
                  private speculation is that he (the number holder) and Mary both knew they weren't
                  legally married." However, in the memorandum from the Acting Director of the Western
                  Program Service Center, it is reported that, "It has been established that she (Mary)
                  had good faith belief in the validity of her marriage to the number holder."
               
               For Social Security purposes, an applicant is considered the widow of a fully insured
                  individual if the courts of the State in which such insured individual was domiciled
                  at the time of his death would find that such applicant and such insured individual
                  were validly married at the time such insured individual died. 42 U.S.C. 416(h)(1)(A).
                  Inasmuch as the insured, Ronald W~, was domiciled in Kentucky at the time of his death,
                  the laws of Kentucky are controlling in the determination of whether Bonnie is the
                  legal widow of the insured.
               
               With regard to which of the two marriages is valid, under Kentucky law, we conclude
                  that Bonnie W~ has not presented sufficient evidence to rebut the presumption of the
                  validity of the second marriage. A similar situation involving two widows was considered
                  in the Kentucky case of Trimble v. Wells, 234 S.W. 2d 683 (1950). The court wrote,
               
               "The presumption is that the (previous) marriage to Gibson continued. But here there
                  is evidence of a second marriage by a legal ceremony with the presumption of its legality
                  and continuity. The validity of (the subsequent) marriage to Trimble may be presumed as having been made without legal impediment. Rose
                     v. Rose, 274 Ky. 208, 118 S.W. 2d 529. These conflicting presumptions of a legal status present
                  a 'knotty question' .... However, the presumption of legality of the ceremony of (the
                  subsequent) marriage to Trimble is rebutted not only by evidence of Gibson, the former husband, but by proof of the
                  effectual dismissal of a divorce suit without judgment having been rendered and without
                  any attempt to show any other similar proceeding."
               
               The Trimble court found the later marriage to be bigamous and void.
               
               In a later case, Gaddy v. Louisville & Nashville
                     Railroad Co., 249 F. Supp. 305 (Ky., 1965), the court held that where the decedent's second wife
                  established her marriage to the decedent, the presumption of the second wife's widowhood
                  could be rebutted by proving by a preponderance of the evidence that the decedent's
                  prior marriage was valid and that its continuity had not been interrupted by death
                  or divorce at the time of the subsequent ceremony. The court further held that where
                  the decedent's first wife proved the validity of her prior marriage to the decedent
                  and its uninterrupted continuity at the time of his subsequent marriage, the decedent's
                  second wife, who had established her marriage to the decedent, could no longer rely
                  on the presumption that she was the decedent's widow but had to come forward and show
                  at least the probability that the decedent, at some time and in some place, did in
                  fact obtain a divorce from his first wife before his marriage to her." Payne
                     v. Payne's Administrator, 290 Ky. 461, 161 S.W. 2d 925 (1942); Scott's Administrator v. Scott, 25 Ky. L. Rcp. 1356, 77 S.W. 1122 (1904). In Gaddy, the court found the presumption of the validity of the last marriage was rebutted
                  where the decedent's first wife produced evidence that no divorce had been obtained
                  in any of the States where the decedent lived or could have lived. The court held
                  it was not necessary to produce such evidence from every State were the decedent may
                  have lived in order to rebut the presumption.
               
               In this claim, although a search of the Los Angeles County Court House records revealed
                  that no final decree of divorce was filed, we do not feel that this single record
                  search is sufficient to rebut the legal presumption of the validity of the last marriage.
                  It is apparent from the file that Ronald W~ resided in Indiana at the time of his
                  marriage to Mary and that he was a resident of Kentucky at the time of his death.
                  It is not necessary that the first wife show that the decedent did not obtain a divorce
                  in any State in which he could have lived; if Bonnie were to obtain evidence that
                  no divorce had been filed in the appropriate courts of the Indiana and Kentucky Counties
                  wherein the decedent is known to have resided, such evidence could be considered as
                  sufficient to rebut the presumption of the validity of the last marriage. Thereupon,
                  Mary W~~ would be required to come forward and show at least some probability that
                  the decedent, at some time and in some place, did, in fact, obtain a divorce from
                  his first wife before his marriage to her. See also OGC opinion, G~, Tom— ~, RA IV (Benedict), July 13, 1981, However, based on
                  the evidence currently in the file, we feel that the presumption of the validity of
                  the last marriage has not been rebutted by a preponderance of the evidence and, thus,
                  that Mary is the legal widow.
               
               You have also asked whether, if Bonnie W~ successfully rebuts the presumption of the
                  validity of the last marriage, she would then be estopped from denying the validity
                  of her divorce from the decedent. As noted earlier, no divorce has been established
                  in this claim. It was determined in a precedent OGC opinion (H~, Robert ~ RA IV [Harper]
                  December 23, 1948) that estoppel is a matter of procedure and not of substantive law;
                  therefore, estoppel does not give rise to a valid divorce. Thus, it is our opinion
                  that inasmuch as a divorce cannot be created by the application of estoppel, Bonnie
                  is not now estopped from asserting the legal rights arising out of her marriage to
                  the decedent.
               
               The doctrine of laches is also considered inapplicable here. Laches arise to bar an
                  individual from asserting his rights when an individual has made an unreasonable delay
                  or neglected to do that which he was obliged to do or in duty bound to do. See OGC opinion G~, Tom, supra. In the case of Fightmaster v. Leffler, 556 S.W. 2d 180 (Ky. 1977), laches was discussed in the context of a vendor/vendee
                  dispute. The court wrote, at 183, that mere lapse of time,
               
               "is not the only element to be considered in applying the rule. A more important consideration
                  is whether delay in asserting the claim has worked to such prejudice or disadvantage
                  to parties adversely interested or such changed conditions have occurred in the meantime
                  that enforcement of the claim is rendered inequitable. There is no fixed rule by which
                  to measure the degree of laches which is sufficient to bar enforcement of a right.
                  Each case must be determined according to its own particular facts and circumstances."
               
               Generally, there is no basis for a contention that the complainant has been guilty
                  of laches where the rights of third persons are not involved and the situation of
                  the defendant has not been materially changed by reason of the complainant's delay
                  in asserting his rights. Noble
                     v. Gallardo y Seary, 223 U.S. 65, 32 S.Ct. 194; Loagg
                     v. Herbert, 215 U.S. 546, 30 S.Ct. 218; Southern
                     Pine Lumber Co. v. Ward, 208 U.S. 126, 28 S.Ct. 239; 27 Am. Jur. 2d, Equity §162 et seq. In this claim, the
                  second marriage occurred within a year from the time the decedent and his first wife
                  separated. Since that time, the second wife's position has not materially changed
                  by reason of the first wife's delay in asserting her rights. Apparently, both widows
                  promptly asserted their rights following the death of the insured.
               
               We are aware of only one Kentucky case in which laches was applied to bar the first
                  wife from asserting the invalidity of her divorce from the deceased husband. In the
                  1901 case of Asbury
                     v. Powers, 23 Ky. 1622, 65 S.W. 605, the court found that after a lapse of 25 years and after
                  the remarriage and death of the husband, the first wife was barred by laches from
                  attacking the divorce on the ground of no jurisdiction.
               
               A later Kentucky case considered but did not apply the doctrine of laches in a dispute
                  between two individuals each claiming to be a decedent's widow. In Payne v. Payhe's Administrator, supra, the first wife married the decedent in 1908, they separated sometime between
                  1927 and 1934, the decedent married his second wife in 1938 and lived with her until
                  his death in 1940. Neither widow knew of the existence of the other marriage. The
                  first wife asserted her rights on learning of the husband's death four months after
                  the fact and was not barred by laches (discussed only in the context of the four months
                  delay) from suing the administrator who had distributed the estate to the second wife.
               
               In the more recent Gaddes case (1965), discussed supra, the husband married his first
                  wife in 1954; the date of their separation is not reported. In 1962, the husband married
                  his second wife and they lived together until his death in 1964. Each wife's knowledge
                  or lack of knowledge of the other's marriage is not reported. Neither estoppel nor
                  laches was considered and the first wife, was found to be the decedent's lawful widow
                  and entitled to any damages recovered as the result of his death.
               
               In view of the strong Kentucky public policy against marrying where one party has
                  a living, undivorced spouse (prohibited at Ky. Rev. Stat §402.020 and bigamy declared
                  a Class D felony at Ky. Rev. Stat. 3 530.010) we conclude that neither estoppel nor
                  laches would be readily invoked to bar a first wife from asserting the continuance
                  of the marital relation once she has rebutted the presumption of the validity of the
                  second marriage.
               
               Thus, we conclude that Bonnie W~ has not presented sufficient evidence to rebut the
                  presumption of the validity of the last marriage, and, consequently, Mary W~ is the
                  decedent's legal widow. If, however, Bonnie W~ provides additional evidence, as discussed
                  above, to rebut said presumption, then Mary W~ would be required to show at least
                  some probability that the decedent, at some time and in some place, did, in fact,
                  obtain a divorce from his first wife. If, based on the additional evidence, Bonnie
                  W~ is found to be the decedent's legal widow, she would not be barred by the application
                  of either estoppel or laches from asserting her legal rights.