Photo tour: Royal ship christenings through the years

Catherine, Duchess of Cambridge, was eight months pregnant with heir-to-the-British-throne Prince George when she cut a ribbon to release a bottle of champagne against the hull of the Royal Princess during its christening ceremony.

A bottle of champagne smashes against the hull of the Royal Princess during the ship's naming ceremony on June 13, 2013.

Among the most notable royals to christen a cruise ship in modern times was Britain's Princess Diana, who christened Princess Cruises' original Royal Princess in 1984.

Shown here touring the pool deck of the original Royal Princess in 1984, Princess Diana continued a tradition of royal christenings for passenger ships that dates back at least a century.

Royal christenings have been a long tradition at Cunard Line, which is based in England and has ties to the British monarchy. Here, Britain's Queen Mary christens Cunard's Queen Mary at the John Brown , Company shipyard in Clydebank, Scotland on Sept. 26, 1934. The 2,139-passenger ship was named in honor of the queen, who was the wife of King George V.

Cunard's Queen Mary arrives in New York for the first time on June 1, 1936.

Just four years after the christening of the Queen Mary, on Sept. 27, 1938, Britain's new Queen Elizabeth christened Cunard's Queen Elizabeth at the John Brown , Company shipyard. The 2,283-passenger ship was named in honor of the queen, who was the wife of King George VI and mother of the current Queen Elizabeth II (who attended the ceremony as a young princess).

Britain's Princess Elizabeth (the future Queen Elizabeth II) christens Cunard's Caronia in Clydebank, Scotland on Oct. 30, 1947. The ship sailed for the line until 1967.

Since becoming Britain's monarch in 1952, Queen Elizabeth II has gone on to christen three more Cunard ships. Here, she presides over the naming of the 1,777-passenger Queen Elizabeth 2 on Sept. 20, 1967.

Built at the John Brown , Company shipyard in Clydebank, Scotland, Cunard's 70,327-ton "QE2," as the Queen Elizabeth 2 often was called, was named after Cunard's original Queen Elizabeth and sailed as the line's flagship until the arrival of the Queen Mary 2 in 2004.

Britain's Queen Elizabeth II made a final visit to the Queen Elizabeth 2 on June 2, 2008 -- more than 40 years after christening the vessel. The Queen Elizabeth 2 retired from the Cunard fleet shortly thereafter.

Queen Elizabeth II also christened Cunard's current flagship, the 2,620-passenger Queen Mary 2, in Southampton, England on Jan. 8, 2004.

Cunard's Queen Mary 2 was given a fireworks salute as it set sail for the first time after being christened by Queen Elizabeth II. At 148,528 tons, it is the largest passenger ship ever named by a monarch.

One of Cunard's two newest ships, the Queen Victoria, was named by Prince Charles' second wife, Camilla, the Duchess of Cornwall. Here, Prince Charles and Camilla are seen at the christening ceremony in Southampton, England on Dec. 10. 2007.

Prince Charles and Camilla, Duchess of Cornwall, with officers of Cunard's Queen Victoria at the ship's christening on Dec. 10, 2007.

Queen Victoria captain Paul Wright gives Britain's Prince Charles and Camilla, Duchess of Cornwall, a bridge tour before the ship's naming on Dec. 10, 2007.

Camilla, Duchess of Cornwall, poses with Queen Victoria's White Star Bellmen on the day of the ship's naming, Dec. 10, 2007.

Cunard's Queen Victoria arrives in Southampton, England on Dec. 7, 2007, three days before being christened by Camilla, Duchess of Cornwall.

Seventy-two years after her mother christened Cunard's original Queen Elizabeth, Britain's Queen Elizabeth II presses a button to release a bottle against the bow of the latest ship to carry the name. The ceremony took place on Oct. 11, 2010 in Southampton, England.

Queen Elizabeth II receives applause at the naming ceremony for Cunard's Queen Elizabeth on Oct. 11, 2010.

Queen Elizabeth II is joined on stage by Carnival Corp. Chairman and CEO Micky Arison (left) during the naming ceremony for Cunard's Queen Elizabeth on Oct. 11, 2010. Miami-based Carnival Corp. acquired Cunard since 1998.

The crew of the Queen Elizabeth welcomes Queen Elizabeth II aboard the vessel before the ship's naming on Oct. 11, 2010.

Another line with a long tradition of royal christenings is Holland America. Here, Princess Margriet of The Netherlands presides over the naming of the line's 1,848-passenger Oosterdam in Rotterdam on July 29, 2003.

The Oosterdam is one of more than half a dozen Holland America ships christened by a Dutch royal over the past century. Princess Margriet alone has christened three Holland America vessels.

Another Dutch royal who has christened multiple Holland America ships is the former Queen Beatrix of The Netherlands (now Princess Beatrix). Here, she tours the bridge of Holland America's 2,104-passenger Eurodam after christening the vessel on July 1, 2008.

Holland America fans look on as the Eurodam arrives in Rotterdam on June 29, 2008, two days before being christened by Queen Beatrix of The Netherlands.

A bottle of champagne breaks against the hull of Holland America's Eurodam during its christening by Queen Beatrix of The Netherlands on July 1, 2008.

Residents of Rotterdam were treated to fireworks on July 1, 2008 after Queen Beatrix of the Netherlands christened the vessel.

Holland America CEO Stein Kruse presents a flower arrangement to Queen Beatrix of the The Netherlands at the ship's christening ceremony on July 1, 2008.

Princess Maxima of The Netherlands (the future Queen Maxima) christens Holland America's 2,106-passenger Nieuw Amsterdam IV on July 4, 2010.

Princess Maxima of The Netherlands tours the bridge of Holland America's Nieuw Amsterdam IV after christening the vessel on July 4, 2010. To her left is Stein Kruse, CEO of Holland America.

In a twist on the tradition of royal christenings, Royal Caribbean's Allure of the Seas was named on Nov. 29, 2010 by Dreamworks character Princess Fiona. Royal Caribbean had a partnership with Dreamworks to bring the company's characters to its ships. In this picture with Princess Fiona, from left to right, are: Adam Goldstein, president and CEO of Royal Caribbean International; Richard Fain, chairman and CEO of parent company Royal Caribbean Cruises Ltd.; and Capt. Hernan Zini, master of Allure of the Seas.

Britain's Princess Diana at the christening of Princess Cruises' original Royal Princess in 1984.

Catherine, Duchess of Cambridge, tours the bridge of the Royal Princess before christening the ship on June 13, 2013.

Catherine, Duchess of Cambridge, at the christening ceremony of Princess Cruises' Royal Prinecss.

Catherine, Duchess of Cambridge, arriving for the christening ceremony of Princess Cruises' Royal Princess on June 13, 2013.

Catherine, Duchess of Cambridge, watches as the a Moet and Chandon champagne bottle breaks against the hull of the Royal Princess.

Catherine, Duchess of Cambridge, talks with the Royal Princess' captain on the ship's bridge.