Question: Which cruise line founded in Norway boasts the largest cruise ships and passenger vessels ever built?
Context: MS "Regal Empress was a cruise ship that recently operated for Imperial Majesty Cruise Line.  She was built in 1953 by Alexander Stephen & Sons at Glasgow, Scotland as the ocean liner SS "Olympia for the Greek Line.  Greek Line withdrew the "Olympia" from service in 1974.  Following an extended lay-up period and reconstruction into a diesel-engined Caribbean cruise ship, the ship re-emerged in 1983 as MS "Caribe I" for Commodore Cruise Line.  In 1993 she was sold to Regal Cruise Line and received her final name.  She operated for Imperial Majesty Cruise Line from 2003 until 2009.  The "Regal Empress" was also the last vintage passenger ship to regularly sail from the United States. Premier Cruises was a cruise line holding company formed in the early 1990s that focused on the family cruise market as well as on developing cruise operations in new geographic markets.  The company's business focus was to acquire older cruise vessels, refurbish these vessels in order to offer "traditional cruise experiences", operate the vessels in geographic areas, such as Europe and south/Central America, which the major operators such as Carnival Cruise Line, Norwegian Cruise Line and Royal Caribbean International were not focusing at the time, and to market their cruises largely to European and South American customers through strategic marketing partnerships with some of the major tour and travel groups in the world such as Thomson Holidays in the U.K, TUI in Germany, Fritidsresor in Scandinavia, Alpitour in Italy and Pullmantur in Spain (subsequently acquired by Royal Caribbean International for $800 million,) as well as through more than a dozen operators in south / Central America such as CVC in Brazil (which was acquired by the Carlyle Group [63.6%] in January 2010 for $250 million).  The company was operating out of its main offices in Cape Canaveral and Miami, Florida. Fiesta Marina Cruises was an experimental short-lived subsidiary cruise line of Carnival Cruise Lines.  The cruise line was marketed toward the Latin/Spanish-speaking population, residing in the United States and abroad.  The cruise line sailed out of San Juan, Puerto Rico and Caracas, Venezuela.  The cruise line operated only one ship, the "Fiesta Marina".  The ship was named in Miami, Florida on October 18, 1993.  The cruise line was a total marketing failure and was dissolved in September 1994.  The "Fiesta Marina" was sold to Epirotiki Cruises to sail as the "Olympic".  In 2007, the Carnival Corporation started a joint-partnership with the Orizonia Corporación to start a new cruise line called Iberocruceros.  Just like Fiesta Marina, the new cruise line was marketed toward the Latin/Spanish-speaking population.  The cruise line operated out of South America and Europe, independently from Carnival, but was managed by Costa Cruises.  Iberocruceros was closed in 2014 and its ships transferred to Costa or elsewhere. MS "Independence of the Seas" is a "Freedom"-class cruise ship operated by the Royal Caribbean cruise line that entered service in April 2008.  The 15-deck ship can accommodate 4,370 passengers and is served by 1,360 crew.  She was built in the Aker Finnyards Turku Shipyard, Finland, builder of "Freedom of the Seas "and "Liberty of the Seas", her sister ships of the "Freedom "class.  At 154,407 GT, she joined "Freedom of the Seas" and "Liberty of the Seas" as the largest cruise ships and passenger vessels yet built.  She is 1112 ft long, and typically cruises at 21.6 kn .  The vessel operates from Fort Lauderdale, Florida during the Fall and Winter months and Southampton, England during the Spring and Summer months. The "Fantasy" class is a cruise ship class operated by Carnival Cruise Lines.  The first vessel of the class, "Fantasy", entered service in 1990.  All eight vessels of the class were constructed by Kvaerner Masa Yards, in Helsinki, Finland.  The "Elation" and the "Paradise" differ from the other ships of the class in that they have "Azipod" azimuth thrusters.  They were also the last cruise ships built with the lifeboats only on the upper deck.  This class utilizes a "modern ocean/cruise liner" design, with all of its cabins situated within the hull and only a handful of suites on the superstructure, similar to the Holiday Class cruise ships built in the late 1980s.  The Fantasy-class is the only class currently in service for Carnival initially built with only a few balcony cabins. Majesty Cruise Line is a Norwegian cruise line probably known for owning the Norwegian Majesty from 1992 to 1997.  Majesty Cruise Line was a more upmarket brand created by Dolphin Cruise Line in 1993.  Their first ship, the Royal Majesty, was originally ordered by Birka Line for their 24-hour cruises out of Stockholm.  Following the bankruptcy of builders Wärtsilä, the contract was resold to Majesty Cruise Line and the vessel was completed as Caribbean cruise ship Royal Majesty in 1992.  She initially worked three- and four-night cruises out of Florida, but in 1995 opened a new summer Boston-Bermuda route, terminating at St George's rather than the usual Hamilton in Bermuda.  Royal Majesty returned to Florida in the winter.  In June 1995 she ran aground on Rose and Crown shoal of Nantucket Island, due to a combination of faulty GPS and inadequate watch being maintained.  Royal Majesty was 17 miles off course.  She remained aground for 24 hours before tugs towed her off.  In 1997, a second ship was added to the fleet, the Crown Majesty (previously Crown Dynasty).  For the 1997 season, she operated cruises which had already been arranged for Crown Dynasty, but at the end of that season both ships passed to Norwegian Cruise Line (NCL).  Royal Majesty was sold to NCL, being renamed Norwegian Majesty, and soon received a similar lengthening to Norwegian Wind/Dream.  Crown Majesty which had been chartered from Effjohn International, had her charter transferred to NCL. Royal Caribbean International is a cruise line brand founded in Norway and based in Miami, Florida, United States.  It is owned by Royal Caribbean Cruises Ltd.  s of March 2017 , the line is operating 24 ships, has six additional ships on order, and controls 21.9 percent of the cruise market worldwide.  All ships under the Royal Caribbean International brand have names ending with "of the Seas" (e.g. "Empress of the Seas" ) a practice which began in 1991. P&O Cruises is a British/American cruise line based at Carnival House in Southampton, England, operated by Carnival UK and owned by Carnival Corporation & plc.  Originally a constituent of the Peninsular and Oriental Steam Navigation Company, P&O Cruises is the oldest cruise line in the world, having operated the world's first commercial passenger ships in the early 19th century.  It is the sister company of, and retains strong links with, P&O Cruises Australia.  P&O Cruises was de-merged from the P&O group in 2000, becoming a subsidiary of P&O Princess Cruises, which subsequently merged with Carnival Corporation in 2003, to form Carnival Corporation & plc.  P&O Cruises currently operates eight cruise ships with a total passenger capacity of 14,970 and a 5% market share of all cruise lines worldwide.  Its most recent vessel, MV "Britannia", joined the fleet in March 2015. Ocean Star Cruises is a cruise line based in Mexico City, Mexico.  It was founded in 2010, the first Mexican cruise line.  The first ship in its fleet was the MV "Ocean Star Pacific" (launched on 9 July 1970 for RCCL), purchased in December 2010 to become the first ship in the fleet.  She entered service on 10 April 2011.  The cruise ship sailed the waters of the Mexican Riviera, with embarkation ports at Acapulco and Manzanillo.  The company planned to expand its fleet to include six additional newly built vessels in the next 5 years.  Ocean Star Cruises no longer operates cruise ships. MS "Liberty of the Seas" is a Royal Caribbean International "Freedom"-class cruise ship which entered regular service in May 2007.  It was initially announced that she would be called Endeavour of the Seas, however this name was later changed.  The 15-deck ship accommodates 3,634 passengers served by 1,360 crew.  She was built in 18 months at the Aker Finnyards Turku Shipyard, Finland, where her sister ship, "Freedom of the Seas", was also built.  Initially built at  gross tonnage (GT) , she joined her sister ship, "Freedom of the Seas", as the largest cruise ships and passenger vessels then ever built.  She is 1111.9 ft long, 184 ft wide, and cruises at 21.6 kn .
Answer: Royal Caribbean International