Departing 16 April 2028, passengers can sail on all four Cunard "Queens" back to back in a single 40-night sailing. Prices start from £5,459 per person based on two guests sharing a Britannia Inside stateroom.
Guests begin on Queen Victoria from Southampton, sailing to the Norwegian fjords. They then join Queen Mary 2 for a short European voyage to Le Havre and Zeebrugge, gateway to Bruges.
The third leg is a 16-night sailing on board Queen Anne, visiting Hamburg, Stockholm and Oslo, including the "Four Queens Celebration", where it will dock overnight in Liverpool.
The journey concludes with an eight-night Mediterranean sailing on Queen Elizabeth to Rome.
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McAlister told TTG: "This will appeal to explorers and inspiration seekers looking for something distinctive, as well as loyal Cunard customers who find it difficult to choose between our iconic Queens, or who may have experienced one or two ships and now wish to complete the collection in a single voyage.
"The 40-night back-to-back sailing across the full fleet is the first of its kind and should be positioned as a genuine once-in-a-lifetime experience. The celebration in Liverpool offers customers the chance to be part of Cunard history."
However, she noted some potential barriers to book including the length of the itinerary and having to arrange a UK-bound flight from Rome.
But she added: "There are various options to suite a wide range of budgets. Considering the length of the journey, the number of destinations, and the opportunity to experience all four ships in one trip, it represents strong value for a unique travel experience.
"This is an iconic moment for Cunard and the first time guests can experience all four Queens and such diverse itineraries within a single journey. It’s incredibly rare for the full fleet to come together in this way, making it a genuine one-off experience in our modern history."
The itinerary is part of Cunard's 2028 programme, featuring 190 voyages in 36 countries. Cunard World Club members will enjoy exclusive early access to all new voyages from 2pm on Tuesday 19 May, before all bookings are on sale to all guests from 2pm on Wednesday 20 May.
