In some monarchies , such as the United Kingdom , an interregnum is usually avoided due to a rule described as `` the king is dead , long live the King '' , i.e. the heir to the throne becomes a new monarch immediately on his predecessor 's death or abdication . In some monarchies , such as the United Kingdom , an interregnum is usually avoided due to a rule described as `` The King is dead . Long live the King '' , i.e. the heir to the throne becomes a new monarch immediately on his predecessor 's death or abdication .