Operation Shader, the UK's contribution to the fight against the so-called Islamic State (IS), is more than six years old.
Since 2014, RAF aircrew based in Cyprus have flown daily missions over Iraq and Syria as part of a coalition of nations fighting the so-called Islamic State, also known as Daesh.
The final towns and cities once held by the militant group were liberated in 2019, but Operation Shader will continue, until IS is considered to be completely eradicated.
Major General Christopher Ghika, Deputy Commander of the Global Coalition's Combined Joint Task Force, told Forces News two years ago: "This is an organisation which set its stall in 2014 in holding physical terrain, today they hold nothing and therefore it's a significant moment.
"It isn't the end of the group or the campaign because IS still present a threat to Iraq, Syria, the region and the world, and that's why the global coalition will continue its operations.
"They have now been driven underground but they are still credible, they have sleeper cells in Iraq and Syria and that's why the coalition's operations will continue.
"It's absolutely not over. The operation isn't over because ISIS are still present even though discredited," he added.
Defence Secretary Ben Wallace has previously warned that IS remains the "most significant terrorist threat" to the UK.
In December 2020, a UK Government report said the extremist group is taking advantage of COVID-hit forces and a lower profile, and is driving the UK's terror threat.
What Is Operation Shader?
The operation began as a humanitarian aid mission but has grown into a complicated mission to try to defeat IS.
The coalition launched Operation Roundup in 2018 to clear the remains of the terror group in Syria.
Air Commodore Roddy Dennis, the UK's Air Component Commander, said at the time: "We're targeting that hardcore element that's left.
"What we see ourselves now is in that final stage of removing those hardened fighters that have sought solace somewhere down in the southern/eastern part of Syria and we're having really good success at closing that out.
"I'm very confident that we will see the ultimate demise of Daesh in the southeastern part of Syria, but it will take some time to do that."
RAF Tornado GR4: A Key Component
One of the RAF aircraft that played a key role in Shader until its retirement in 2019 was the Tornado GR4.
Involved from the very start of the operation, they gathered intelligence and launched hundreds of airstrikes against IS.
Based at RAF Akrotiri in Cyprus as part of Operation Shader, the aircraft flew near-daily missions over Iraq and Syria, targeting IS fighters.
Squadron Leader Colin Bolstrom was a Tornado weapons systems operator who completed several Shader tours.
Earlier in the mission, he said he had seen the fight against IS evolve over time.
"The range of missions the Tornados completed over the years has changed,” he said.
"When I first arrived in Shader we flew aid from this hangar over to Mount Sinjar and supporting refugees.
"We're now supporting the defeat of Daesh, dropping weapons and providing support.
"The most intensive period is when we're targeting, especially over Mosul."
Thousands of people turned out to see the fast jet fly over various locations over three days across the country to say farewell to the Tornado in 2019.
In January 2019, Tornados returned to the UK from operations for the very last time.
RAF Voyager Tanker: Op Shader's Backbone
Based on an Airbus A330 aircraft, the Voyager is part transport plane, part filling station.
The tanker carries about 100 tonnes of fuel and has kept the fighter jets flying with air-to-air refuelling.
On average, RAF jets will refuel two or three times per sortie, depending on the aircraft.
The older Tornados took up to six tonnes each time, while the more economical Typhoons only need three.
RAF Typhoon: Tornado Abilities Transferred
The Typhoons joined the war on so-called Islamic State in late 2015, when Parliament voted to extend the fight against IS into Syria.
The RAF has eight of them based at Akrotiri in Cyprus.
The aircraft are armed with an internal 27mm Mauser cannon, plus short range air-to-air missiles (ASRAAM), as well as Enhanced Paveway II and Paveway IV.
Earlier this year, the jet began carrying and using Storm Shadow and Brimstone bombs, as well as Meteor air-to-air missiles.
Tornado weapon capabilities were transferred to the Typhoon, including the addition of the Brimstone missile.
Following the Tornado's retirement and in F-35's operational infancy, the Typhoon was for a time the UK's sole frontline jet.
F-35B: Shader's Latest Addition
The Lightning jets flew alongside Typhoon aircraft over Iraq and Syria in support of Operation Shader.
The first mission took place on 16 June over Syria, with two F-35Bs taking part.
Since then, the jets have flown a further 12 sorties from RAF Akrotiri.
In June 2020, F-35s flew their first combat missions from HMS Queen Elizabeth, as part of Op Shader.
The F-35B was designed to operate from austere, short-field bases and a range of air-capable ships – including the Queen Elizabeth-class aircraft carriers.
It can also take off and land conventionally from longer runways at major bases.
In January, a £76m aircraft support contract was signed to help ensure the UK's fleet of F-35 jets is ready for combat operations across the globe.
A £550m contract for new surface attack missiles for the Lightning jets was also signed in January.
Cover image: Typhoons taxi at RAF Akrotiri before a night mission (Picture: MOD).