Exercise Warfighter is run by the US Army to test its ability to plan and conduct large-scale modern combat operations in a realistic multi-domain simulation.
More than 1,300 soldiers from the 3rd (UK) Division, as well as the 7th Infantry Brigade, deployed to military bases Fort Hood and Fort Bliss in Texas, USA.
The British brigade was integrated into a US Division, joining troops from 1 (United States) Armoured Division and for the first time, 3e Division of the French Army, to form a multinational warfighting corps.
The 10-day exercise was an opportunity to unify real-world armour and troops from both sides of the Atlantic for a simulated battlefield to test their warfighting readiness and future agility, the Army said.
In total, Warfighter involved more than 17,000 troops, contractors and senior military advisors.
It was led by United States Army Lieutenant General Pat White, Commanding General III Corps, who called the exercise a "training success".
Brigadier Paul Tennant, who visited during Exercise Warfighter, said: "The British Army collaborates with the US Army on many exercises, and all of them play an important part in perpetuating the extraordinarily close relationship between the two.
"But Warfighter is the biggest, the most complex, the most demanding and the most important.
"It is the one which tests the most fundamental skills of the warfighting division and support to it was my number one priority for the year."
Preparations for the exercise started almost a year ago and included lectures from both UK and US former retired 3 and 4-star Generals and a validation exercise, Ex CERBERUS, held on Salisbury Plain, Wiltshire.
General James McConville, US Army Chief of Staff, said: "This is one of the largest exercises we've ever done of this type in the United States, and we had two countries coming to the US during this challenging period.
"They overcame some significant obstacles to include COVID and because of their untiring efforts they were able to produce a world-class exercise that makes us a stronger army, and quite frankly makes us a stronger ally and partner with two very important partners and allies."
Cover image: Exercise Warfighter (Picture: MOD/British Army).