The sailings are among a number of world cruises to get underway this month.
Festivities included a firework display in the city.
The ships’ itineraries will mirror a number of port calls by RMS Laconia and RMS Samaria during their first sailings.
RMS Laconia, RMS Samaria
RMS Laconia made its maiden voyage on May 25, 1922, sailing from Southampton to New York City.
RMS Samaria was completed in 1922 and was operated by Cunard until 1955.
Cunard revealed earlier this week that it will celebrate 100 years since it introduced onboard photographers and launched its first world voyage with a photo exhibition curated by world-renowned photographer Mary McCartney.