They are the largest and most powerful ships ever built for the Royal Navy.
Both HMS Queen Elizabeth and HMS Prince of Wales are both commissioned into the fleet, although they are currently at varying stages in their journey to becoming operational.
HMS Queen Elizabeth, which is set to be ready for operations in 2021, has left Portsmouth to begin flight trials with British fighter jets in UK waters for the first time.
Meanwhile, HMS Prince of Wales only arrived in Portsmouth for the first time in November after undergoing its first round of sea trials.
The Queen Elizabeth-class ships are the Royal Navy's first aircraft carriers to be built since HMS Ark Royal was scrapped in 2010.
12 Key Facts On The Carriers
1) The project to build HMS Queen Elizabeth and sister ship HMS Prince of Wales cost more than £6 billion.
2) Each aircraft carrier weighs 65,000 tonnes and has a top speed of 25 knots.
3) The flight deck of Queen Elizabeth is 280m long and 70m wide - enough space for nearly three football pitches.
4) The ship is the second in the Royal Navy to be named Queen Elizabeth. A ship of the same name was planned in the 1960s but was never constructed.
5) Prince of Wales is the seventh ship to carry the name, with the first being launched in 1765.
6) Each carrier will have a total crew of 679, increasing to around 1,600 when a full complement of F-35B jets and Crowsnest helicopters are embarked.
7) There are around 364,000 metres of pipes inside each ship.
8) Both Queen Elizabeth-class carriers have two 33-tonne propellers, designed to deliver around 50,000 horsepower each.
9) Both HMS Queen Elizabeth and HMS Prince of Wales will keep 45 days' worth of food in its stores.
10) The entire Ship's Company of 700 can be served a meal within 90 minutes - 45 minutes when at action station.
11) Each Queen Elizabeth-class aircraft carrier has a total of 16 decks, comprised of nine decks from the hull to the flight deck and a further seven in each of the two islands.
12) There is more than 250,000 km of electrical cable and more than 8,000 km of fibre optic cable in each of the ships.
Cover image: Royal Navy.