Operation Shader is the operational code name used for the UK's contribution to the US-led mission against so-called Islamic State (IS).
The final towns and cities once held by the militant group were liberated in 2019, but Operation Shader will continue, with IS not being completely defeated as an organisation.
Last year, a Government report found IS is "driving" the UK's terror threat while global defences have become sidetracked by the coronavirus pandemic.
In January, Defence Secretary Ben Wallace said IS still remains the "most significant terrorist threat" to the UK.
The mission has been running for more than six years, beginning in August 2014.
Airstrikes over Syria were first launched in December 2015, following approval from the British Government.
The UK is the second-largest contributor behind the US, with jets flying missions from RAF Akrotiri in Cyprus.
Since Op Shader began, the RAF has conducted more than a thousand airstrikes over Iraq and Syria, using more than 4,300 weapons launched from Tornado, Typhoon and Reaper aircraft.
The UK has flown more than 8,000 sorties providing strikes, surveillance and reconnaissance, air-to-air refuelling and transport.
History of Operation Shader
The British operation against so-called Islamic State began in Iraq on 26 September 2014, following a formal request for assistance by the Iraqi government.
In October 2014, the UK operation extended to Syria, where the RAF conducted several surveillance flights. MQ-9 Reaper drones based in Cyprus were responsible for 30% of aerial surveillance over Syria.
Tornado jets were involved from the beginning of the mission, until the aircraft's retirement in 2019.
Typhoon aircraft joined the operation in late 2015 when Parliament voted to extend the air campaign against Daesh to Syria.
The RAF also used Sentinel, Sentry and Voyager aircraft.
In September 2017, the RAF carried out its 1,000th airstrike against Daesh targets.
At the same time, then-Defence Secretary Sir Michael Fallon announced an Iraq and Syria Operational Service Medal as part of his visit to Iraq on the eve of Operation Shader's three-year anniversary.
In 2018, the coalition launched Operation Roundup to clear the remains of the terror group in Syria.
This was followed by the UK's most advanced warplane, the F-35B, successfully completing its first operational missions in 2019.
Two F-35Bs flew alongside Typhoon aircraft over Iraq and Syria in support of Operation Shader, with the first mission taking place on 16 June 2019.
In June 2020, F-35s flew their first combat missions from HMS Queen Elizabeth, as part of Shader.
How many Armed Forces personnel have been deployed?
Personnel from across the tri-services are involved in Op Shader.
At the end of 2018-19, about 1,200 servicemen and women were deployed on Operation Shader.
About two-thirds of them were based within the region supporting the air campaign and in key staff roles at coalition headquarters, while remaining personnel were on the ground in Iraq providing training and military advice.
According to the Ministry of Defence (MOD), approximately 1,200 UK personnel are currently deployed on Op Shader.
Royal Air Force
The RAF plays a key role in Op Shader, with combat aircraft flying from Cyprus.
In 2014/15 a total of 1,950 RAF personnel were deployed, this increased to 2,230 by 2017/18.
British Army personnel are also involved in Op Shader on the ground.
There are currently 100 British troops in Iraq in a non-combat role, although this is set to increase.
They have been on the ground spread across three main sites: Camp Taji, Union II and Erbil.
Together with coalition partners, they provide training and equipment to Iraqi Security Forces and Kurdish Security Forces.
According to 2018/19 figures from the MOD, British troops have been helping to train more than 94,000 Iraqi Security Forces.
In 2014/15, a total of 60 Royal Navy personnel took part in Operation Shader, rising to 80 by 2017/18.
The UK has trained more than 120,000 Iraqi forces, including thousands of Kurdish Peshmerga, in weapons maintenance, counter IED, medical and engineering skills.
About 1,100 British personnel are involved in supporting counter-IS operations in the region, including 400 in Iraq supporting training.
Kurdish Peshmerga have been provided with 40 heavy machine guns, more than a million rounds of ammunition and £600,000 of equipment.
Personnel from across the tri-services are also deployed with the Global Coalition's headquarters across the Middle East.
How many militants have died from Op Shader airstrikes?
RAF air strikes in Iraq and Syria killed and injured an estimated 4,315 enemies with just one civilian fatality, according to estimated figures released by the Ministry of Defence several years ago.
This data suggested that of the 4,315 combatants targeted, 4,013 were reported to have been killed (93%) while 302 (7%) survived with injuries.
In total, 75% of those estimated to have been killed or injured were in Iraq and 25% in Syria.
Comparing this to other nations, the United States military revealed at least 1,257 civilians died as a result of 33,921 US-led coalition airstrikes between August 2014 and January 2019.
The Royal Australian Air Force (RAAF) also said it was "possible" that as many as 18 civilians were unintentionally killed during airstrikes over Iraq.
The one confirmed civilian fatality as a result of RAF air strikes came during a strike to engage three Daesh fighters in Raqqa.
The civilian was on a motorbike and crossed into the strike as it was happening.
Cover image: An RAF Typhoon fighter jet on Operation Shader (Picture: MOD).