This appeal raises for the first time the question of subject matter jurisdiction of our state courts over civil actions between members of the Eastern Band of Cherokees living on the reserva*3tion, following the recent creation of a tribal court system by the Eastern Band.1
It is axiomatic that personal and subject matter jurisdiction are essential prerequisites to entry of a valid court order. It is also beyond dispute that a defendant may challenge a court’s subject matter jurisdiction at any stage of the proceedings, but may not raise the issue of personal jurisdiction for the first time on appeal. In the case at bar, defendant failed to make timely challenges to the personal jurisdiction of the state court in the 1980 default action and the 1983 contempt hearing; thus defendant’s argument that the trial court lacked personal jurisdiction is overruled. Defendant’s contention that the state court lacked subject matter jurisdiction and was thus powerless to enter either the 1980 default judgment or the 1983 contempt order requires more detailed discussion.
The general subject of Indian law is well beyond the scope of this opinion and we confine ourselves to the issue of jurisdiction over civil suits arising on tribal lands. A few well-established principles of law bear repeating at the outset, beginning with the proposition that federal power to regulate Indian affairs is plenary and supreme.2 The states generally have only such power over Indian affairs on a reservation as is granted by Congress,3 while *4the tribes retain powers inherent to a sovereign state, except as qualified and limited by Congress.4
To ask what entity possesses subject matter jurisdiction over a cause of action is to inquire about the way the power of governing has been allocated. The answer turns as much upon the history and political structures of our nation as upon legal theory in the area of Indian law, where tribes and the federal and state governments have all exercised varying degrees of sovereignty at different times. We turn therefore to an examination of the history of the relationship between the Eastern Band of the Cherokee and the state and federal governments for insight into the ways decision-making power has been distributed.
A detailed history of the Cherokees of North Carolina is set out in The Cherokee Trust Funds, 117 U.S. 288 (1886), United States v. Wright, 53 F. 2d 300 (4th Cir. 1931) and therefore we will not fully repeat those accounts here. It is sufficient to note that the Cherokee Indians were once one of several dominant Indian tribes occupying what is now North Carolina, South Carolina, Tennessee, Georgia and Alabama and that the tribes were sovereign entities with inherent powers to govern and settle disputes among their members, W. Canby, American Indian Law (1981). Upon the arrival of white settlers, the sovereignty of the tribes diminished, as first the British and then the United States governments asserted ownership of Cherokee lands. Under the Treaty of New Echota of 1835, the Cherokee Nation ceded all lands east of the Mississippi River to the United States and agreed to move west. About 1,200 Cherokees eluded the forced removal, however, and remained in North Carolina, where their rights and status were somewhat uncertain for many years. Following a rather complex series of land transactions, the Cherokee reservation, known as the Qualla Boundary lands, was established in western North Carolina. In 1924, pursuant to an act of Congress, 43 Stat. 376, the United States took title to the Cherokee land, holding those lands in trust for the benefit of the Eastern Band and placing certain restrictions upon alienation and taxation of the land, United States v. Wright, supra. The term of the trust relationship was extended indefinitely by the Indian Reorganization Act of 1934, 48 Stat. 984.
*5The foregoing brief history of the Eastern Band sufficiently illustrates the drastic changes in the relationship between the Eastern Band and the state and federal governments. Before 1835, the North Carolina Cherokees were members of a separate, sovereign nation with inherent powers of self-government. By the terms of the Treaty of New Echota, the federal government, through its plenary power over Indians, provided that those Cherokees remaining in the state would thereafter be subject to state law. By 1868, the North Carolina Cherokees were accorded state citizenship.
Meanwhile, the Cherokees’ relationship with the federal government continued to evolve as federal policies toward Indians changed. As early as 1868 Congress instructed the Secretary of the Interior to take “the same supervisory charge of the Eastern or North Carolina Cherokees as of other tribes of Indians.”5 Later acts of Congress also indicated that the Eastern Band had been accorded full tribal status by the federal government, despite the fact that tribal members were also citizens of North Carolina.6
Federal recognition of the Eastern Band as an Indian tribe has at least two major implications for the issue of state jurisdiction: (1) the federal government continues to maintain plenary power over the Eastern Band, a fact which strictly limits extensions of state power, Williams v. Lee, 358 U.S. 217 (1959), S. Sherick, “State Jurisdiction Over Indians As A Subject of Federal Common Law: The Infringement-Preemption Test,” 21 Ariz. L. Rev. 85 (1979), and (2) the Eastern Band, like all recognized Indian *6tribes, possesses the status of a “domestic dependent nation”7 with certain retained inherent sovereign powers, accord, Eastern Band of Cherokee Indians v. Lynch, 632 F. 2d 373 (4th Cir. 1980). These two principles also constitute the test for determining the scope of state court jurisdiction over members of an Indian tribe, referred to by some authorities as the infringement-preemption test.8
Under the preemption prong of the test, state power over Indian tribes is determined in light of the federal government’s plenary power over all Indians. State regulations which conflict with federal enactments are void, and even if there is no directly conflicting federal enactment, state action may be barred if Congress has indicated an intent to “occupy the field” and prohibit parallel state action. S. Sherick, supra at 88. See e.g., McClanahan v. Arizona State Tax Comm’n, 411 U.S. 164 (1973).
If there is no applicable federal enactment, the state action must be examined under the infringement prong of the test, to determine if tribal sovereignty has been infringed upon. S. Sherick, supra at 87, F. Cohen, Handbook of Federal Indian Law, at 349-50 (1982).
In applying the infringement-preemption test to the facts before us, we turn first to examine the validity of the July 1980 default judgment. Defendant contends that by 1953 at the very latest, Congress had enacted legislation which preempted the field of Indian law and eliminated state court jurisdiction except as provided by the Act. Defendant contends that Public Law 280, codified at 18 U.S.C. § 1162 (1976 & 1983 Supp.); 28 U.S.C. § 1360 (1976 & 1983 Supp.) provides the exclusive method by which states can assume jurisdiction over Indians residing within their borders. Under the terms of P.L. 280, five states (later six), were *7automatically granted “jurisdiction over civil causes of action . . . to which Indians are parties which arise in . . . Indian country . . . to the same extent that such State . . . has jurisdiction over other civil causes of action.”9 Section seven of the act, which has since been repealed, permitted states other than the five which were ordered to assume jurisdiction, to obtain jurisdiction by legislative action if they so desired. North Carolina was not among the states ordered to assume jurisdiction, nor has our legislature acted to assume jurisdiction under section seven of the act.
In 1968, the Indian Civil Rights Act10 was enacted, permitting states to assume jurisdiction over civil cases involving Indians and arising in Indian country by consent of the tribe affected. The Eastern Band has never given formal consent to the assumption of state jurisdiction pursuant to the Indian Civil Rights Act, Sasser v. Beck, 40 N.C. App. 668, 253 S.E. 2d 577, disc. rev. denied, 298 N.C. 300, 259 S.E. 2d 915 (1979).
Defendant contends that passage of P.L. 280 and the Indian Civil Rights Act preempted the entire field of state jurisdiction over Indians, and that states which have not acted pursuant to the federal legislation are without jurisdiction over civil cases arising on reservations. The United States Supreme Court, however, has recently recognized that prior, lawfully assumed state jurisdiction over some civil cases involving Indians survived the passage of P.L. 280. In Three Affiliated Tribes of the Fort Berthold Reservation v. Wold Engineering, — U.S. —, 52 U.S.L.W. 4647 (1984), the Court noted that “[njothing in the language or legislative history of Pub. L. 280 indicates that it was meant to divest States of pre-existing and otherwise lawfully assumed jurisdiction.”11
*8Plaintiff, on the other hand, contends that the state obtained jurisdiction over the Eastern Band pursuant to the Treaty of New Echota and that this jurisdiction was not divested by the passage of P.L. 280, the Indian Civil Rights Act, or any other action of Congress. We agree. The purpose12 of P.L. 280 was to provide law enforcement for reservations which lacked adequate law enforcement and means of dispute settlement. At least through 1980, the members of the Eastern Band were free to avail themselves of the state courts for settlement of their disputes. We do not believe that Congress intended to preempt state court jurisdiction where the Indian tribe had no court system of its own. A rule holding that P.L. 280 was intended to cut off state jurisdiction over civil suits between reservation Indians which had no tribal court system would have had the opposite effect from that intended by Congress, by depriving the tribe of the state court forum, without providing an alternative. Our position is strengthened both by the language of Wold, supra, and by the failure of Congress to enact specific legislation barring assertion of North Carolina jurisdiction despite notice of the operation of state courts in this area for nearly thirty years.13
*9Decisions of the United States Supreme Court which seem to indicate that P.L. 280 and the Indian Civil Rights Act are the sole means by which a state may obtain jurisdiction over civil suits involving Indians are distinguishable on the grounds that none of the decided cases deal with an assertion of jurisdiction by a state pursuant to a treaty, over an Indian tribe without a tribal court system of its own.14 A contrary rule, while perhaps under a literal interpretation of broadly-worded statutes, would serve neither *10the congressional purpose behind P.L. 280 nor the ultimate welfare of the members of the Eastern Band, as it would require the invalidation of nearly thirty years of state court judgments voluntarily sought by members of the Tribe. We hold, therefore, that Congress has not preempted the field of state court assumption of subject matter jurisdiction over tribes which are without their own court system.
We turn now to the infringement prong of the test to determine if assertion of state jurisdiction in 1980 unduly infringed upon the Eastern Band’s inherent right of self-government. While the Eastern Band has a great interest in regulating the domestic relations of its members, it does not appear to us that entry of the default judgment unduly infringed upon tribal sovereignty, as the tribe at that time had chosen not to exercise its rights of self-government in the area of dispute resolution. See Three Affiliated Tribes of the Fort Berthold Reservation v. Wold Engineering, supra. Defendant’s contention that the Swain County District Court lacked subject matter jurisdiction to enter the 1980 default judgment must therefore be overruled.15 Accord, Little Horn State Bank v. Stops, 170 Mont. 510, 555 P. 2d 211 (1976), cert. denied, 431 U.S. 924 (1977), see also Sasser v. Beck, supra, affirming the trial court’s jurisdiction over a civil action occurring on the reservation, but failing to employ federal preemption doctrine analysis in reaching its results.16 F. Cohen, supra at 350.
*11We now consider whether the state court retained jurisdiction to enforce the default judgment once the tribal court began operation on 28 July 1980. Plaintiff correctly notes that as a general rule, subject matter jurisdiction is determined when the initial complaint is filed, and later events do not deprive the court of jurisdiction. In re Peoples, 296 N.C. 190, 250 S.E. 2d 890 (1978), cert. denied, 442 U.S. 929 (1979), 20 Am. Jur. 2d Courts §§ 142, 148 (1965 & 1983 Supp.). It is also true that while a court loses jurisdiction over a cause after it renders a final decree, it retains jurisdiction to correct or enforce its judgment, Whitmer v. Whitmer, 243 Pa. Super. 462, 365 A. 2d 1316 (1976), cert. denied, 434 U.S. 822 (1977); State ex rel Taylor v. Carey, 74 Mont. 39, 238 P. 597 (1925); 21 CJS Courts § 94 (1940 & 1983 Cum. Supp.). This general rule, however, is insufficient to override application of the infringement-preemption test to this case. Accord Joe v. Marcum, 621 F. 2d 358 (10th Cir. 1980).
We need not reach the issue whether state court jurisdiction was preempted by federal legislation after 28 July 1980, as the question before us may be resolved under the infringement prong of the test. It is clear that any exercise of state power after the creation of the Indian court system would unduly infringe upon the tribe’s asserted right of self-government. Williams v. Lee, supra. Accordingly, we hold that the judgment of the Swain County District Court of 3 May 1983 must be reversed and remanded.
Reversed and remanded.
Judge Becton concurs.
Judge JOHNSON concurs in the result.