Sixteen soldiers from Royal Horse Artillery are taking part in the Army's biggest training exercise of the year.

Normally based at Tidworth in Wiltshire, the soldiers from B Battery are attached to the Royal Household Cavalry as part of the two-month deployment in which they are simulating the role of the enemy.

Among them is Sgt Rob Fletcher, 29, whose first daughter Annabelle was born two weeks before he travelled to Canada in August.

Sgt Fletcher, originally from Leicester and now living in Amesbury, has been deployed twice to Iraq and twice to Afghanistan.

He said while he regretted not being with his wife Elizabeth at such an important time, many people in the Army experience greater hardship.

"I can't complain because it's not as bad as if I was in Afghanistan - it's part of military life that you risk missing out on these things," he said.

"I get to text home every day and have the occasional chat on the internet.

"But I can't wait to get home to Elizabeth and to see how Annabelle has grown up while I've been away."

Major Paul Britton, 34, originally from Birmingham, said: "Playing the enemy is a good way of testing both our own guys and those they are fighting against.

"We can operate without the ethical, moral and legal constraints that we would normally be under.

"That is a good opportunity to adjust our mind-set and for us all to learn some valuable lessons about what we could face in future conflicts."

Captain Holly Saunders, 26, originally from Finchingfield, Essex, was deployed to Afghanistan in 2011.

She said the exercise represented a chance to return to conventional warfare as opposed to a counter insurgency operation.

She added: "My role has been to operate as a fire support team commander attached to a tank squadron which basically involves dropping heavy artillery.

"For many of the guys, particularly the younger ones, their only experience is of Afghanistan.

"As that comes to an end, it is important we focus on the different challenges we could face in the future."

Fusilier Lewis Barker, 22, originally from East London, is also based at Tidworth. He served in Afghanistan last year and was one of the soldiers called upon to respond to the bombing of a Mastiff armoured vehicle in which three men from the Royal Regiment of Scotland were killed.

He said: "My role was to help form the protective cordon to secure the scene.

"The start of my tour had been quite quiet but when something like that happens it brings home the importance of what you are doing."

As part of the Canada deployment, Fusilier Barker took part in recent tank hunting night training.

This involved using laser equipment to act as a rocket launcher.

"It is certainly different to the way the British Army usually functions," he added.

"It has been good fun and an interesting challenge."