The exercises, stretching from Finland to North Macedonia, will see troops join forces with Nato and other allies backed by military hardware including 72 Challenger 2 tanks, 120 Warrior armoured fighting vehicles and 12 AS90 tracked artillery guns.
Lieutenant General Ralph Wooddisse, a senior army commander, said the exercises planned over the next two months were fundamental to "the defence of Europe and the deterrence of Russian aggression".
It comes with Nato redrawing its defence strategy on its eastern flank and countries such as Poland, Estonia and Latvia increasing military spending after Russia invaded Ukraine, prompting fears of further aggression by the Kremlin.
“The security of Europe has never been more important,” said UK Defence Secretary Ben Wallace.
“These exercises will see our troops join forces with allies and partners across Nato and the Joint Expeditionary Force in a show of solidarity and strength in one of the largest shared deployments since the Cold War.
“Operating across Europe, the British Army will stand alongside partners, combining our capabilities and shared values, promoting peace and security.”
The programme follows the defence secretary’s “Future Soldier” announcement last November, setting out how the British Army is evolving into a more lethal, agile and global force in line with the UK government’s Integrated Review.
The exercises showcase the British Army’s capabilities and readiness, demonstrating the central role it plays in Nato deterrence, it said in a statement.
Troops from the Queen’s Royal Hussars have deployed to Finland this week to take part in Exercise Arrow, which will see them working with a non-Nato force at a time when the country is contemplating a move to join the Western Alliance. Finland's neutral status is a leftover pillar of the Cold War and Moscow has signalled its readiness to escalate its strategic posture in response.
The deployed UK troops will be embedded into a Finnish Armoured Brigade, with participation from other partners including the US, Latvia and Estonia. The exercise will improve the ability of British and Finnish troops to work alongside each other as part of the Joint Expeditionary Force, deterring Russian aggression in Scandinavia and the Baltic states, a Ministry of Defence statement said.
High readiness forces from the Lead Armoured Task Force and Air Manoeuvre Task Force will also take part in the drills.
Next month Exercise Hedgehog will see the Royal Welsh Battlegroup and the Royal Tank Regiment exercising on the Estonia-Latvia border alongside 18,000 Nato troops, including soldiers from France and Denmark, who are part of the British-led Nato enhanced Forward Presence. Hedgehog is the biggest military exercise in Estonia and takes place every four years.
Alongside Exercise Hedgehog, Exercise Defender in Poland will continue until late May, with 1,000 soldiers from the King’s Royal Hussars Battlegroup and C Squadron of the Light Dragoons deployed alongside troops from 11 partner nations including Poland, Denmark and the US.
Exercise Swift Response, which also began this week, includes elements of 16 Air Assault Brigade Combat Team and 1 Aviation Brigade Combat Team operating alongside their French, American, Italian and Albanian counterparts in North Macedonia.
In addition to the army’s programme, the UK will establish a major headquarters in the Baltic region, in support of the Joint Expeditionary Force.