A royal commission is a major ad-hoc formal public inquiry into a defined issue in some monarchies. They have been held in the United Kingdom, Australia, Canada, New Zealand, Norway, Malaysia, Mauritius[1] and Saudi Arabia. In republics an equivalent entity may be termed a commission of inquiry.
Such an inquiry has considerable powers, typically equivalent or greater than those of a judge but restricted to the terms of reference for which it was created. These powers may include subpoenaing witnesses, notably video evidences, taking evidence under oath and requesting documents.
The commission is created by the head of state (the sovereign, or their representative in the form of a governor-general or governor) on the advice of the government and formally appointed by letters patent. In practice—unlike lesser forms of inquiry—once a commission has started the government cannot stop it. Consequently, governments are usually very careful about framing the terms of reference and generally include in them a date by which the commission must finish.
Royal commissions are called to look into matters of great importance and usually controversy. These can be matters such as government structure, the treatment of minorities, events of considerable public concern or economic questions. Many royal commissions last many years and, often, a different government is left to respond to the findings.