Why can a marriage involve the laws of more than one country?

A marriage may involve the laws of more than one country because legal events, such as marriage, are often not confined to a single jurisdiction. When a marriage touches upon multiple countries—for instance, if the parties are from different nations, reside in a country other than their own, or marry abroad—the legal systems of those involved countries may claim jurisdiction or have applicable laws.1

In the context of conflict of laws, courts must determine which country's laws govern specific aspects of the union. Historically, legal systems have used various "connecting factors" to resolve these differences, such as:1

• Lex loci celebrationis: The law of the place where the marriage ceremony was performed.2
• Domicile or Habitual Residence: The place where the parties live or have their primary legal home, which often influences family law determinations.3
• Nationality: Historically used in civil-law countries to determine the applicable law for an individual.3

Because national laws regarding marriage requirements, validity, and rights vary significantly, conflicts arise when these systems intersect, requiring specific procedures to determine which law applies to the marriage's formation or its legal consequences.1