Since the start of the US and Israel’s war with Iran earlier this year, militias have been targeting the remaining US and UK forces stationed at Irbil air base.
Hundreds of Nato troops stationed in Baghdad left the country in March as tensions rose.
A BBC team visited the coalition base in Irbil in April this year, during a fragile ceasefire between the US and Iran.
They were forced to circle the base in an RAF transport aircraft while drones were being launched nearby.
At the height of the US bombing campaign against Iran, the coalition base was being targeted by up to 28 drones and missiles a day.
RAF Regiment Gunners, who were among the last British military personnel stationed there, had shot down more than 100 drones in the first six weeks of the war. Many of the attack drones were being launched by Iranian-backed militias in Iraq.
On Wednesday, signalling the end of the mission, the MoD paid tribute to UK personnel who had contributed to the counter-IS mission.
It said they had provided “valuable support, training and assistance” to more than 111,000 members of the Iraqi Security Forces, including more than 21,000 Peshmerga forces in the semi-autonomous Kurdistan Region.
It also said the RAF had conducted thousands of sorties, striking more than 2,300 IS targets. The RAF is expected to continue flying missions over neighbouring Syria, to prevent the remnants of IS from gaining a foothold.
The Pentagon said the US would continue to provide “targeted training and intelligence support” to its Iraqi partners.
US Central Command said the coalition’s joint taskforce remained operational and was now based in Jordan.
US forces will also continue their mission against IS in Syria, where the UN estimates that the group has up to 3,000 fighters.
This is the third time US and UK forces have withdrawn from Iraq.
Tens of thousands of US and British troops were deployed to the country in 1991 following Saddam Hussein’s invasion of Kuwait.
They returned to Iraq in 2003, when US President George W Bush ordered Operation Iraqi Freedom to remove the dictator from power and eliminate weapons of mass destruction that turned out not to exist.
The fierce sectarian insurgency that engulfed Iraq following the invasion cost tens of thousands of lives, including those of nearly 4,500 US military personnel and 179 British military personnel.
US and UK forces left Iraq in 2011, only to return three years later, when IS threatened to take control of the country.
