LEGAL PRINCIPLE: JURISDICTION – Jurisdiction of Court – Applicable Law Being Law at Time Cause of Action Arose
PRINCIPLE STATEMENT
The law applicable to an action is the law existing at the time the cause of action arose and not the law existing when the jurisdiction of the court is invoked; by the combined effect of constitutional and statutory provisions, the court would have no jurisdiction to entertain a suit relating to chieftaincy if the cause of action arose before the date when the new Constitution came into force; the first question to answer is: when did the cause of action arise? This is a determining question.
RATIO DECIDENDI (SOURCE)
"The law applicable to an action is the law existing at the time the cause of action arose and not the law existing when the jurisdiction of the court is invoked. - Mustapha v. Governor of Lagos State (supra). By the combined effect of section 161(3) of the 1963 Constitution and section 14(c) of the Obas and Chiefs of Lagos Edict 1975, the court would have no jurisdiction to entertain a suit relating to that chieftaincy if the cause of action arose before 1st October 1979 when the 1979 Constitution came into force - Mustapha v. Governor of Lagos State & Ors. (1987) 2 NWLR (Pt.58) 539; (1987) (Pt.1) NSCC 632. It follows that the first question I have to answer is: when did the cause of action arise in this case? This is a determining question in this case."
EXPLANATION / SCOPE
Applicable law is determined by when cause of action arose, not when suit was filed. This temporal principle serves: certainty (parties’ rights determined by law when they arose), preventing retrospective application of new laws, and maintaining legal stability. When cause of action arose: that law governs rights and remedies, later law changes don’t affect accrued rights, and jurisdiction depends on law at accrual time. This matters particularly for: constitutional transitions (new constitutions changing jurisdiction), statutory amendments affecting rights, or ouster clauses enacted after cause accrual. In chieftaincy disputes: if cause arose when ouster clause existed (pre-1979 Constitution), courts lack jurisdiction despite later Constitution granting it; if cause arose after constitutional change (post-1979), courts have jurisdiction. “Determining question” means: threshold issue affecting jurisdiction, must be decided before proceeding, and determines whether court can hear case. Courts must: identify when cause of action arose, determine applicable law at that time, and assess jurisdiction under that law. This prevents: retrospective law application, uncertainty about applicable law, and jurisdictional gaps from transitional periods. The principle protects vested rights while recognizing legal evolution