delivered the opinion of the court:
This is an appeal from a decree of the circuit court of Hardin County which dismissed for want of equity a complaint whereby the appellant, John Pyle, sought to- quiet title to the mineral estate in 80 acres of land and to remove as clouds upon his title a tax deed conveying such estate and certain leases made by the holder of the tax deed.
William Pyle, the father of appellant, acquired title to the land in question by deeds executed in 1886 and 1903. Proof was made that he paid all taxes assessed for the years 1903 through 1911, and both his son and neighbors testified he was in possession and farmed the land until his death in 1931. By the terms of William Pyle’s will, which was duly probated, the mineral estate in the 80 acres was severed from the surface estate and title to the former became completely vested in appellant when his mother’s life tenancy was terminated by death in 1932. He thus became seized of a separate estate in the minerals with all the rights of an owner of land, and subject to all the laws of possession, *550conveyance and taxation. (Miller v. Ridgley, 2 Ill.2d 223 ; Deverick v. Bline, 404 Ill. 302; 26 I.L.P., Mining, Oil & Gas, sec. 11.) Such estate could not be lost by mere nonuser or abandonment of the mineral interest, (Uphoff v. Trustees of Tufts College, 351 Ill. 146; 26 I.L.P., Mining, Oil & Gas, sec. 49,) but could be lost by adverse possession, (Kinder v. La Salle County Carbon Coal Co. 301 Ill. 362; Jilek v. Chicago, Wilmington & Franklin Coal Co. 382 Ill. 241,) and is also considered to be “land,” within the meaning of section 7 of the Limitations Act, (Ill. Rev. Stat. 1953, chap. 83, par. 7,) which may be lost to one who gains title by the payment of taxes for seven years under color of title. Catlin Coal Co. v. Lloyd, 176 Ill. 275.
Appellant was a resident of California when his parents died, having moved there in 1917, and he testified that he first learned of his mineral estate at the time of his mother’s death in 1932. He continued his residence in California until 1946, in which year he moved to Galatia, Illinois, described as being 40 miles from the county seat where the tax and property records concerning his mineral estate were kept, and 35 miles from the land itself. By appellant’s own admission, he did not at any time between 1932 and 1954 either visit the land or concern himself with the use of his mineral estate. Neither did he pay taxes at any time or attempt to learn of their status. In 1954 appellant’s interest in his mineral estate was aroused by a geologist who approached him for a lease and who gave him the information that the estate had been sold to Haggle Ferrell for delinquent taxes. Thereafter appellant filed this proceeding to quiet title and although his complaint offers to do equity, there is no showing that he ever made a tender of the back taxes to Ferrell, or negotiated with him. With regard to taxes on the mineral estate, which were assessed separately from those of the surface estate, appellant testified he had never received notice of assessments and de*551nied having received any notice relating to the tax sale proceedings.
Various tax records introduced in evidence, including a notice of sale, a certificate of purchase, an affidavit for deed, and a tax deed, establish that appellant’s mineral estate was sold in 1936 for delinquent taxes of 1935. The purchaser, Haggie Ferrell, received a tax deed in 1938 when the estate was not redeemed. Ferrell paid the taxes assessed for 1936 and 1937 and, after receiving his tax deed, paid the taxes for and including all years up to 1955. In total, therefore, he paid taxes for 20 consecutive years with 18 of the payments being under the color of title afforded by his tax deed. Whether Ferrell took the possession of the mineral estate necessary to perfect a title under section 7 of the Limitations Act, (see: Robertson v. Bachmann, 352 Ill. 291; Wylie v. Fisher, 337 Ill. 488; Travers v. McElvain, 200 Ill. 377; Catlin Coal Co. v. Lloyd, 176 Ill. 275,) remains doubtful from the evidence in the record. However, in the view we take, a decision on that issue is unnecessary to this opinion. During 1951 Ferrell caused the title to the mineral estate to be placed in joint tenancy with his wife and title was so held when this action was commenced in 1954. Ferrell died before the cause was heard, thus it is his widow, Bessie Ferrell, who is the principal appellee in this court. The complaint alleges that Otis Lamar, Aluminum Corporation of America and the Shell Oil Company are third parties claiming some interest in the mineral estate by virtue of leases executed by Ferrell. The Shell Company filed an answer admitting its claim as the assignee of a recorded oil-and-gas lease executed by Ferrell on March l3i I953? but did not participate further in the cause; Lamar and the Aluminum Corporation filed no answers and were defaulted.
Appellant’s complaint for equitable relief was predicated on the theory that the tax deed to the mineral estate was *552void for various incidents of nonconformance with the statutory requirements for the issuance of a valid tax deed. Appellee Ferrell denied the invalidity of the deed and, in addition, affirmatively defended on the ground of laches, and upon title allegedly perfected under section 7 of the Limitations Act, (Ill. Rev. Stat. 1953, chap. 83, par. 7,) by virtue of seven years payment of taxes, with color of title to vacant lands. The chancellor, without passing upon the other issues, dismissed the complaint for want of equity on the ground that appellant had been guilty of laches. Although appellant has argued to the contrary, it is our opinion the decree must be sustained on that ground.
Laches, or the doctrine of stale demand, as it is sometimes termed, is a defense peculiar to equity which is bottomed on the reluctance to aid one who has knowingly slept upon his rights and acquiesced for a great length of time, (19 Am. Jur., Equity, sec. 489,) and its existence.depends on whether, under all circumstances of a particular case, a plaintiff is chargeable with want of due diligence in failing to institute proceedings before he did. (McCartney v. McCartney, 8 Ill. 2d 494.) Although laches is defined by one authority as such delay in enforcing one’s rights as will work to the disadvantage of another, (30 C.J.S., Equity, sec. 112,) it is, unlike limitations, not a mere matter of time but principally a question of the inequity of permitting the claim to be enforced, an inequity founded upon some change in the condition or relation of the property and parties, and where there is such a change as to make it inequitable to grant relief, it will be refused. (McKey v. McKean, 384 Ill. 112.) Laches is, therefore, such neglect or omission to assert a right, taken in conjunction with a lapse of time of more or less duration and other circumstances causing prejudice to an adverse party, as will operate to bar relief in equity. (Curtis v. Curtis, 398 Ill. 442; Gaffney y. Harmon, 405 Ill. 273; Carlson v. Carlson, 409 Ill. 167.) When an owner brings an action in equity *553to recover land as against the holder of the tax title, the doctrine of laches will apply if the conditions for its application are present. 85 C.J.S., Taxation, sec. 985; cf. Oakley v. Hurlbut, 100 Ill. 204.
What facts will combine to constitute laches is to be determined in the light of the circumstances of each case; however, it is pointed out in 19 Am. Jur., Equity, sec. 498, that a suit is held to be barred on the ground of laches or stale demand “where and only where” the following facts are disclosed: (1) Conduct' on the part of the defendant giving rise to the situation of which complaint is made and for which the complainant seeks a remedy; (2) delay in asserting the complainant’s rights, the complainant having had notice or knowledge of defendant’s conduct and the opportunity to institute a suit; (3) lack of knowledge or notice on the part of the defendant that the complainant would assert the right on which he bases his suit, and (4) injury or prejudice to the defendant in the event relief is accorded to the complainant or the suit is held not to be barred. The facts present in this case meet these requirements and demonstrate conclusively that it would be most inequitable to grant relief to appellant, considering the long delay in bringing suit, the nature of the property interest, and all that he permitted to take place with reference to his mineral estate from the time he became seized of such interest until the time he commenced this suit.
Courts treating upon the doctrine of laches have long recognized that more than ordinary promptness is required of a claimant if the property involved is of a speculative or fluctuating character, (Simpson v. Manson, 345 Ill. 543; Carlock v. Carlock, 249 Ill. 330,) and, because oil and mining property is of such a specially precarious nature and is exposed to the utmost fluctuations in value, have held there is no class of property in which laches is more relentlessly enforced. (Twin-Lick Oil Co. v. Marbury, 91 U.S. 587, 23 L. ed. 328; Sturm v. Wiess, 273 Fed. 457; Medallion *554 Oil Co. v. Hinckley, 92 F.2d 155.) Here we are dealing solely with a mineral estate which had been severed from the surface, and the facts show appellant became aware of his interest, and of its nature, in 1932. Haggie Ferrell, from whom appellee Ferrell derived her title, purchased the appellant’s mineral estate for delinquent taxes in 1936, received a tax deed in 1938, paid taxes for 20 consecutive years, caused a joint interest in the mineral estate to be conveyed to his wife in 1951 and executed an oil-and-gas lease covering such estate in 1953, all without challenge from the appellant. These matters were all of public record, and although appellant claims not to have had notice of any of these matters adverse to his ownership, such public records served as constructive notice to him where, as here, the adverse claimant was not guilty of any affirmative act of deception to prevent suspicion and inquiry. (See: Potts v. Alexander, 118 Fed. 885; Briggs v. Buzzell, 164 Minn. 116, 204 N.W. 548.) The test is not what the appellant knows, but what he might have known by the use of the means of information within his reach with the vigilance the law requires of him. Neagle v. McMullen, 334 Ill. 168; Blaul v. Dalton, 264 Ill. 193.
During the same period of time that Ferrell was establishing and exercising his adverse claim, appellant made no inspection of his property or the property records, did not at any time pay taxes or make inquiry with regard to the tax status, and conducted himself generally in such a manner as to indicate acquiescence both in Ferrell’s title and in his subsequent conduct of conveying and leasing the mineral interest. This negligence and indifference on the part of appellant continued even during the period of eight years which elapsed after his return to Illinois in 1946 and, considering his proximity to both the land and the public records concerning it, occurred at a time when ordinary prudence would suggest he make inquiry into the status of his interest. Had he done so he would have learned his min*555eral estate had been sold for delinquent taxes, and would have discovered the alleged deficiencies in the sale proceedings of which he now complains some 16 years after the tax deed was issued and recorded. Appellant testified he was unaware the minerals were assessed separately from the surface. By weight of authority, however, ignorance of the law or legal rights will not excuse delay in bringing suit. LeGout v. LeVieux, 338 Ill. 46; Breit v. Yeaton, 101 Ill. 242; 30 C.J.S., Equity, sec. 128f.
In addition to the neglect and delay which attended the appellant’s prosecution of this action, we may consider that a party is guilty of laches which ordinarily bars the enforcement of his right where he remains passive while an adverse claimant incurs risk, enters into obligations, or makes expenditures for improvements or taxes. (See: 30 C.J.S., Equity, sec. 118.) Here it is undisputed that Ferrell, after waiting 15 years for appellant to redeem his land or to assert himself against the tax title, incurred the risk and obligations attendant to a lease of the mineral estate for oil and gas, and that he expended money for the taxes on the premises for a period of 20 consecutive years. We may consider too that the rule of laches is particularly applicable where the difficulty of doing entire justice arises through the death of parties to the transaction complained of. (Neagle v. McMullen, 334 Ill. 168; Carlock v. Carlock, 249 Ill. 330.) Ferrell, the grantee of the tax deed appellant seeks to cancel, died before the cause could be heard and thus important evidence on the issue of possession under the tax deed was lost. While Ferrell’s testimony might not have been conclusive, its loss, after the long delay of appellant in bringing his suit, is but another factor pointing up the inequity of granting relief in this case.
Predicated on the circumstance that there is here involved a mineral estate, the character of which necessitated a greater degree of diligence and promptness than would be otherwise required, it is our opinion that the circuit *556court of Hardin County properly found appellant guilty of laches. Our conclusion, however, must be considered as being the result of the circumstances peculiar to this case, and not to represent a view that laches of an owner will in all instances serve as a defense to those claiming under tax deeds. Accordingly, the decree dismissing the complaint for want of equity is affirmed.
Decree affirmed.