Quasi in rem refers to court proceedings that primarily affect specific property (the “res”) in order to determine or secure a person’s rights, rather than determining all aspects of that person’s status or liabilities. It is most commonly discussed in the context of jurisdiction and enforcement of judgments. In practice, a court exercises quasi in rem jurisdiction where it uses control over assets within its territory (for example land, bank accounts or moveable property) to adjudicate claims linked to those assets, often where personal jurisdiction over the defendant is limited or disputed. The expression is largely descriptive and rooted in common law and conflict of laws doctrine, rather than being defined in UK or Irish statute. Modern civil procedure in England and Wales, Scotland, Northern Ireland and Ireland has moved away from rigid in personam / in rem / quasi in rem categories, but the terminology still appears in textbooks, older case law and commentary on international jurisdiction and recognition and enforcement of foreign judgments, especially from US sources. Across these jurisdictions, the underlying idea is broadly consistent: the court’s order binds the property within the jurisdiction, rather than conclusively resolving all personal rights of the parties worldwide.