delivered the opinion of the court:
The defendant, John Michael Joseph, asks this court to determine whether the circuit court of Knox County erred in ruling that section 122 — 8 of the Post-Conviction Hearing Act (Ill. Rev. Stat., 1984 Supp., ch. 38, par. 122 — 1 et seq.) violates the separation-of-powers clause of the 1970 Constitution (Ill. Const. 1970, art. II, sec. 1). The statute requires that all post-conviction proceedings “shall be conducted and all petitions shall be considered by a judge who was not involved in the original proceeding which resulted in conviction.” (Ill. Rev. Stat., 1984 Supp., ch. 38, par. 122 — 8.) We granted defendant’s motion for leave to appeal as a matter of right.
The defendant was convicted of murder following a jury trial in the circuit court of Knox County over which Judge Daniel J. Roberts presided. The conviction was reversed on appeal, and the cause was remanded for a new trial. Upon remand, Judge Roberts recused himself, and the cause was assigned to Judge Scott I. Klukos. The second jury trial also resulted in a conviction of murder. The appellate court affirmed this conviction and this court denied leave to appeal.
While the petition for leave to appeal was pending before this court, the defendant filed a pro se petition for post-conviction relief in the circuit court of Knox County. The petition initially came before Judge Klukos. Pursuant to section 122 — 8, the defendant moved to have a judge other than Judge Klukos conduct all the proceedings under the Post-Conviction Hearing Act (Ill. Rev. Stat., 1984 Supp., ch. 38, par. 122 — 1 et seq.). Judge Roberts, in his capacity as the administrative judge for Knox County in the Ninth Judicial Circuit, reassigned the cause to Judge Stephen G. Evans.
The State then filed a motion to have section 122 — 8 declared unconstitutional and to have the cause returned to Judge Roberts for assignment. After a hearing, Judge Evans declared section 122 — 8 unconstitutional as a violation of the principles of separation of powers. Judge Roberts again assigned the cause to Judge Klukos, who issued an order directing the office of the State Appellate Defender to pursue any and all remedies before this court. We allowed defendant’s motion for leave to appeal as a matter of right.
Section 122 — 8 of the Post-Conviction Hearing Act (Ill. Rev. Stat., 1984 Supp., ch. 38, par. 122 — 8) is a legislative enactment which attempts to govern an aspect of judicial procedure. (People v. Ruiz (1985), 107 Ill. 2d 19, 23.) The defendant contends that this provision is constitutional because it neither unduly infringes upon the power of the judiciary, nor conflicts with any rules promulgated by this court.
We note in support of defendant’s position “that a strong presumption of constitutionality attaches to any legislative enactment and that the burden rests upon the challenger to demonstrate its invalidity.” (Sanelli v Glenview State Bank (1985), 108 Ill. 2d 1, .20; Chicago National League Ball Club, Inc. v. Thompson (1985), 108 Ill. 2d 357, 368; Fireside Chrysler-Plymouth, Mazda, Inc. v. Edgar (1984), 102 Ill. 2d 1, 5, appeal dismissed (1984), 469 U.S. 926, 83 L. Ed. 2d 254, 105 S. Ct. 316.) We note also that the wisdom of this legislation is not an issue before this court. People v. J.S. (1984), 103 Ill. 2d 395, 407.
The separation-of-powers clause of our constitution provides: “The legislative, executive and judicial branches are separate. No branch shall exercise powers properly belonging to another.” (Ill. Const. 1970, art. II, sec. 1.) This provision does not contemplate “rigidly separated compartments.” (In re Estate of Barker (1976), 63 Ill. 2d 113, 119; Strukoff v. Strukoff(1979), 76 Ill. 2d 53, 58; see also City of Waukegan v. Pollution Control Board (1974), 57 Ill. 2d 170, 174.) However, this court has held that if a “power is judicial in character, the legislature is expressly prohibited from exercising it.” (Emphasis added.) People v. Jackson (1977), 69 Ill. 2d 252, 256; see also Agran v. Checker Taxi Co. (1952), 412 Ill. 145, 149; People v. Bruner (1931), 343 Ill. 146, 157.
While our constitution does not define the term, this court has stated that “[¡judicial power is the power which adjudicates upon the rights of citizens and to that end construes and applies the law.” (People v. Hawkinson (1927), 324 Ill. 285, 287.) We have recognized that this very general definition may be supplemented by looking to the common law and to the history of our institutions at the time of the adoption of the 1970 Constitution. (People v. Callopy (1934), 358 Ill. 11, 14; People v. Brumfield (1977), 51 Ill. App. 3d 637, 643.) Both of these factors indicate that the administration of our judicial system is an element of the “judicial power” exclusively conferred on the courts.
At common law, it was recognized that the legislative branch was “without power to specify how the judicial power shall be exercised under a given circumstance ***.” (Emphasis added.) (People v. Crawford Distributing Co. (1972), 53 Ill. 2d 332, 338; People v. Spegal (1955), 5 Ill. 2d 211, 219-20.) The legislature was prohibited from limiting or handicapping a judge in the performance of his duties. (5 Ill. 2d 211, 219.) Thus, the concept of “judicial power” included the inherent authority to prescribe and institute rules of procedure. (Agran v. Checker Taxi Co. (1952), 412 Ill. 145, 149; People v. Callopy (1934), 358 Ill. 11, 14-15.) Clearly, this common law prohibition would include matters of how the court was to function, that is matters concerning court administration.
The history of our judicial branch also indicates that court administration falls within the ambit of the courts’ inherent “judicial power.” The Constitution of 1870 (Ill. Const. 1870, art. VI, sec. 1 et seq.) granted to the courts all powers necessary for the complete performance of the judicial function. (People v. Spegal (1955), 5 Ill. 2d 211, 220.) Our present constitution provides that the “[g]eneral administrative and supervisory authority over all courts is vested in the Supreme Court and shall be exercised *** in accordance with its rules.” (Ill. Const. 1970, art. VI, sec. 16.) The words “and supervisory” were added in the 1970 provision to emphasize and strengthen the concept of central supervision of the judicial system. Ill. Ann. Stat., art. VI, sec. 16, Constitutional Commentary, at 527 (Smith-Hurd 1971).
Article VI, section 7, provides that “[s]ubject to the authority of the Supreme Court, the Chief Judge shall have general administrative authority over his court, including authority to provide for divisions, general or specialized, and for appropriate times and places of holding court.” (Emphasis added.) (Ill. Const. 1970, art. VI, sec. 7(c).) When our constitution intends that the legislature is to act in governing the activities of the court, the term “as provided by law” is used as the limiting phrase. (See People v. Brumfield (1977), 51 Ill. App. 3d 637, 643.) For example, the appellate court’s power to directly review administrative actions is limited “as provided by law.” Ill. Const. 1970, art. VI, sec. 6; see also Ill. Const. 1970, art. VI, sec. 7(b).
We have held that, when this court has not acted in an area into which it is arguable that the “judicial power” extends, section 16 of article VI (Ill. Const. 1970, art. VI, sec. 16) does not purport to exclude the legislature from acting in any way which may have a peripheral effect on judicial administration. (Cf. Ill. Ann. Stat., art. VI, sec. 16, Constitutional Commentary, at 528 (Smith-Hurd 1971).) For example, this court has upheld the legislature’s enactment of rules of evidence (People v. Rolfingsmeyer (1984), 101 Ill. 2d 137), of statutes mandating a life sentence for anyone sentenced to imprisonment for more than one murder (People v. Taylor (1984), 102 Ill. 2d 201), and of statutes which affect the proceedings in an action entirely statutory in origin and nature which do not conflict with a rule of this court (Strukoff v. Strukoff (1979), 76 Ill. 2d 53).
However, when the legislature has encroached upon a fundamentally judicial prerogative, we have not hesitated to protect the court’s authority. This court has found that a statute which purported to require judges to state their reasons for imposing a particular sentence violated the separation-of-powers clause (Ill. Const. 1970, art. II, sec. 1). (People v. Davis (1982), 93 Ill. 2d 155, 161-62.) We also found such a violation where the legislature encroached upon the ability of a trial judge to control his own docket after the trial of a cause had begun. (People v. Flores (1984), 104 Ill. 2d 40, 49.) Recently this court held that sections 2 — 1009 and 13 — 217 of the Code of Civil Procedure (Ill. Rev. Stat. 1983, ch. 110, pars. 2— 1009, 13 — 217) could not operate to preclude the court from ruling on a motion to dismiss under Rule 103(b) (87 Ill. 2d R. 103(b)). O’Connell v. St. Francis Hospital (1986), 112 Ill. 2d 273, 282-83.
The defendant argues that section 122 — 8 of the Post-Conviction Hearing Act (Ill. Rev. Stat., 1984 Supp., ch. 38, par. 122 — 8) does not unduly encroach on this court’s administrative and supervisory authority; however, under the principles discussed above, and for the reasons stated below, we find that because of the encroachment in this area of court administration, section 122 — 8 violates the separation-of-powers clause of our constitution (Ill. Const. 1970, art. II, sec. 1).
We do not believe that the legislature has greater latitude to prescribe procedure in this area simply because post-convictión review is statutory in origin (see People v. Slaughter (1968), 39 Ill. 2d 278, 284). Prior to the enactment of this act, the available methods by which a judgment of conviction could be attacked were writ of error, habeas corpus, and corum nobis. (39 Ill. 2d 278, 284.) The Supreme Court of the United States was concerned that this “merry-go-round” was preventing prisoners from pursuing legitimate constitutional challenges to their convictions. (39 Ill. 2d 278, 284, quoting Marino v. Ragen (1947), 332 U.S. 561, 570, 92 L. Ed. 170, 176, 68 S. Ct. 240, 245 (Rutledge, J., concurring, joined by Douglas and Murphy, JJ.).) This concern prompted the enactment of the Post-Conviction Hearing Act (Ill. Rev. Stat., 1984 Supp., ch. 38, par. 122 — 1 et seq.), which was designed to provide a means whereby a prisoner could easily assert his challenge. (See People v. Slaughter (1968), 39 Ill. 2d 278, 284-85.) Although post-conviction relief is statutory in origin, it was designed to implement the common law remedies. The amendment we are now considering was not designed to limit or define the scope of the statutory remedy. (See Strukoff v. Strukoff (1979), 76 Ill. 2d 53, 59-60.) Instead, it directly conflicts with rules of this court and of the circuit court adopted pursuant to the Illinois Constitution of 1970, article VI, sections 16 and 7(c). In Strukoff this court denied that the requirement of section 403(e) of the Illinois Marriage and Dissolution of Marriage Act (Ill. Rev. Stat. 1977, ch. 40, par. 403(e)), by its requirement for a bifurcated hearing, violated the separation-of-powers clause, since dissolution of marriage is entirely statutory in origin and nature. This court noted that the situation in that case was not one “in which a statute directly conflicts with a rule of this court." Strukoff v. Strukoff (1979), 76 Ill. 2d 53, 58.
Assuming that the statute, standing alone, does not represent a violation of the separation-of-powers clause (Ill. Const. 1970, art. II, sec. 1), the legislature is without authority to interfere with “a product of this court’s supervisory and administrative responsibility." (People v. Jackson (1977), 69 Ill. 2d 252, 259.) In other words, if a statute conflicts with a rule of this court adopted pursuant to constitutional authority, the rule will prevail. People v. Cox (1980), 82 Ill. 2d 268, 274; People v. Jackson (1977), 69 Ill. 2d 252, 259.
In this case section 122 — 8 conflicts with Supreme Court Rule 21 (94 Ill. 2d R. 21). That rule provides:
“(a) Appellate Court and Circuit Court Rules. A majority of the Appellate Court judges in each district and a majority of the circuit judges in each circuit may adopt rules governing civil and criminal cases which are consistent with these rules and the statutes of the State ***.
(b) General Orders. The chief judge of each circuit may enter general orders in the exercise of his general administrative authority, including orders providing for assignment of judges ***.” (Emphasis added.) 94 Ill. 2d Rules 21(a), (b).
The defendant argues that section 122 — 8 of the Post-Conviction Hearing Act (Ill. Rev. Stat., 1984 Supp., ch. 38, par. 122 — 8) does not conflict with Rule 21 because subparagraph (a) of Rule 21 requires the chief judge of each circuit to assign judges consistent with any applicable statutes, including section 122 — 8. However, Rule 21(a) pertains only to the rule-making authority of the courts. Rule 21(b), which gives the chief judge the authority to enter general orders providing for the assignment of judges, does not require that the general order be consistent with the statutes. Rule 21(b), adopted pursuant to section 7(c) of article VI of our constitution (Ill. Const. 1970, art. VI, sec. 7(c)), earlier quoted, confers power on each chief judge to enter general orders for the assignment of judges, free from any express legislative limitations.
We also note that the defendant’s literal interpretation of Rule 21 would give the legislature unlimited authority over administration of all Illinois courts. It is the undisputed duty of this court to protect its judicial powers from encroachment by legislative enactments in order to preserve an independent judiciary. (Agran v. Checker Taxi Co. (1952), 412 Ill. 145, 149.) If the rules of each circuit must be consistent with every legislative enactment regarding procedure, even where the subject matter is properly within the ambit of the “judicial power,” this duty would be totally abandoned. Rule 21(a) should be properly interpreted as requiring only that each circuit’s rules be consistent with statutes that do not unduly infringe upon the “judicial power.”
The defendant also argues that this court, in promulgating our Rule 1 (87 Ill. 2d R. 1), has recognized that the Code of Criminal Procedure of 1963 (Ill. Rev. Stat. 1983, ch. 38, par. 100 — 1 et seq.), which includes the Post-Conviction Hearing Act (Ill. Rev. Stat., 1984 Supp., ch. 38, par. 122 — 1 et seq.), can govern trial court procedure and administration, and that the legislature may create different rules for particular kinds of actions. Rule 1 provides that “[t]he rules on proceedings in the trial court, together with the Civil Practice Law and the Code of Criminal Procedure, shall govern all proceedings in the trial court ***.” 87 Ill. 2d R. 1.
Again, as with Rule 21(a) (94 Ill. 2d R. 21(a)), we cannot agree with the defendant’s reading of this rule which would require this court to abandon its duty to protect the authority of the judicial branch of government. (Agran v. Checker Taxi Co. (1952), 412 Ill. 145, 149.) The proper reading of this rule contemplates that the statutes mentioned, so long as they do not unduly encroach on the “judicial power,” and the rules promulgated in these areas should complement one another.
In summary, article VI, section 1, of the Illinois Constitution of 1970 vests the judicial power in the supreme court, an appellate court, and the circuit courts. The supervisory and administrative authority over all the courts is vested in the supreme court, to be exercised in accordance with rules. (Ill. Const. 1970, art. VI, sec. 16.) Subject only to the authority of the supreme court, the chief judge in each circuit has general administrative authority over his court. (Ill. Const. 1970, art. VI, sec. 7(c).) Our Rule 21(b) gives the chief judge authority to enter general orders, including orders for the assignment of judges. (94 Ill. 2d R. 21(b).) The chief judge of the Ninth Judicial Circuit designated Judge Roberts as the administrative judge of Knox County with authority to assign judicial duties to the judges who are regularly assigned to that county. Thus Judge Roberts’ authority to assign the post-conviction petition in this case to a judge flowed directly from the provisions of the constitution and of the rule of this court cited above. Section 122 — 8 of the Post-Conviction Hearing Act (Ill. Rev. Stat., 1984 Supp., ch. 38, par. 122 — 8) directly interferes with this judicial authority of assignment.
Finally, the defendant maintains that if section 114— 5(a) of the Code of Criminal Procedure of 1963 (Ill. Rev. Stat. 1983, ch. 38, par. 114 — 5(a)), which allows for the substitution of judges upon the defendant’s motion, does not violate the separation-of-powers clause (Ill. Const. 1970, art. II, sec. 1), then section 122 — 8 should not be held to do so. However, the defendant has cited no decisions where the issue of the constitutionality of section 114 — 5(a) was before an Illinois court. We, of course, express no opinion on the validity of any other statutes regulating judicial procedure here; therefore, we need not address this contention.
We find that the State has sufficiently rebutted the presumption of constitutionality afforded to section 122 — 8 of the Post-Conviction Hearing Act (Ill. Rev. Stat., 1984 Supp., ch. 38, par. 122 — 8). For the reasons stated above, the order of the circuit court of Knox County is affirmed.
Order affirmed.