In 1997, it merged with the Greek cruise line Celebrity Cruises and changed its name from Royal Caribbean Cruise Line to Royal Caribbean International. At the same time, Royal Caribbean Group was formed as Royal Caribbean Cruises Ltd. to serve as a holding company that owned both Celebrity Cruises and Royal Caribbean International. The next year, the last of the company's older vessels, "Song of America" and "Sun Viking", were retired. In 1998, "Vision of the Seas" came into service, the last of the Vision-class ships.