A royal barge is a vessel that is used by a monarch for ceremonial processions, and (historically) for routine transport, usually on a river or inland waterway. It may also be known as a state barge, and may be used on occasion by other members of a royal family, heads of state, or particular VIPs.
Traditionally royal barges were used by European monarchies such as United Kingdom, France, Belgium, and Sweden, and Southeast Asian monarchies such as Siam, Burma, Brunei, Riau and Cambodia.
In more recent years, royal barges have only been used in the United Kingdom, Sweden and Thailand.