This is Prince Harry firing at the Taliban during a front-line clash in Afghanistan.

Manning a powerful .50 calibre machine gun for the first time, Harry helped Gurkha troops repel an insurgent attack on the southernmost British position in Helmand.

Crouching on sandbags, an open box of ammunition at the ready next to him, the prince pumped rounds across 500 metres of cratered no-man's-land using only distant puffs of smoke as his target.

Trained as a battlefield air controller, Harry was working on JTAC Hill, a heavily-defended British position within sight of Taliban trenches, when 16 to 20 Taliban were spotted moving forward, preparing to attack. As a Gurkha rifleman fired off a Javelin missile, the order went out to man the machine guns.

In the ensuing rush it was Harry - just three weeks into his tour in Afghanistan when this picture was taken in early January - who claimed one of them, seizing the chance to put his training into practice.

"This is the first time I've fired a .50 cal," he admitted with a smile. "It's just no man's land ... they poke their heads up and that's it."

Peering through an arch of sandbags over the abandoned farmland, a shredded piece of sack cloth hanging in front provided the only cover for his firing position.

Half a kilometre away lay "Line Taunton", the heavily fortified trench system marking the start of a Taliban-controlled area extending as far south as the Pakistani border.

"The whole place is just deserted, there are no roofs on any of the compounds, there are craters all over the place, it looks like something out of the Battle of the Somme," he said. Harry's immediate boss, Major Mark Milford, Officer Commanding B Company of the 1st Battalion, the Royal Gurkha Rifles, watched the prince.

"This is the southern border for the coalition troops, this is about as dangerous as it can get."

As an artillery commander at the sharp end of the fighting in Afghanistan, Major Andy Dimmock also insisted that Harry didn't shirk from the more dangerous moments of his duty.

"Because of manpower issues he's doing the forward, sharper end at the moment," Maj Dimmock explained in an interview in January. He added: "There has been a lot of action and he's doing exceedingly well."

Another job for the prince was to direct air strikes. He directed his first bomb attack when two US F15 jets discharged separate 500lb charges on to a Taliban bunker system after being given clearance by the prince - known to pilots only as call sign Widow Six Seven.

A third exploded moments later as Taliban fighters emerged from cover in full view of the aircraft above.

The strike, on New Year's Eve, was the culmination of a three-day aerial surveillance operation spearheaded by the 23-year-old Household Cavalry officer working as a battlefield air controller from a fortified position nearby.

There were to be two separate targets at opposite ends of the bunker system.

Once ready, the pilots signalled "In Hot" to Harry. He then gave them the final go-ahead with the words "Cleared Hot".

It was also a novel experience for those working alongside the prince, one of whom was David Baxter, a 28-year-old battlefield air controller, who mentored Harry.

The former tank driver from Bendooragh near Coleraine in Northern Ireland - who holds the rank of Corporal of Horse in the Household Cavalry Regiment - said: "He's a really down-to-earth person."

"To be honest I don't think anyone thinks of him as third in line to the throne or anything, you just take him at face value as any other Household Cavalry officer," he said.

During long shifts in the battlegroup operations room, it was not long before the two red-heads were sharing jokes.

"He fixed my radio for me so he's a good guy to have on board despite being ginger and Irish," red-headed Harry affectionately joked.

"It's a lethal mix."