Gurkhas have been part of the British Army for almost 200 years, but who are these fearsome Nepalese fighters?
"Better to die than be a coward" is the motto of the world-famous Nepalese Gurkha soldiers who are an integral part of the British Army.
They still carry into battle their traditional weapon - an 18-inch long curved knife known as the kukri.
In times past, it was said that once a kukri was drawn in battle, it had to "taste blood" - if not, its owner had to cut himself before returning it to its sheath.
Now, the Gurkhas say, it is used mainly for cooking.
The potential of these warriors was first realised by the British at the height of their empire-building in the last century.
The Victorians identified them as a "martial race", perceiving in them particularly masculine qualities of toughness.
After suffering heavy casualties in the invasion of Nepal, the British East India Company signed a hasty peace deal in 1815, which also allowed it to recruit from the ranks of the former enemy.
Following the partition of India in 1947, an agreement between Nepal, India and Britain meant four Gurkha regiments from the Indian army were transferred to the British Army, eventually becoming the Gurkha Brigade.
Since then, the Gurkhas have loyally fought for the British all over the world, receiving 13 Victoria Crosses between them.
More than 200,000 fought in the two world wars, and in the past 50 years they have served in Hong Kong, Malaysia, Borneo, Cyprus, the Falklands, Kosovo and now in Iraq and Afghanistan.
They serve in a variety of roles, mainly in the infantry but with significant numbers of engineers, logisticians and signals specialists.
The name "Gurkha" comes from the hill town of Gorkha from which the Nepalese kingdom had expanded.
The ranks have always been dominated by four ethnic groups, the Gurungs and Magars from central Nepal, the Rais and Limbus from the east, who live in villages of impoverished hill farmers.
They keep to their Nepalese customs and beliefs, and the brigade follows religious festivals such as Dashain, in which - in Nepal, not the UK - goats and buffaloes are sacrificed.
But their numbers have been sharply reduced from a World War II peak of 112,000 men, and now stand at about 3,500.
During the two world wars 43,000 men lost their lives.
The Gurkhas are now based at Shorncliffe near Folkestone, Kent - but they do not become British citizens.
The soldiers are still selected from young men living in the hills of Nepal - with about 28,000 youths tackling the selection procedure for just over 200 places each year.
The selection process has been described as one of the toughest in the world and is fiercely contested.
Young hopefuls have to run uphill for 40 minutes carrying a wicker basket on their back filled with rocks weighing 70lbs.
Prince Harry lived with a Gurkha battalion during his 10 weeks in Afghanistan.
There is said to be a cultural affinity between Gurkhas and the Afghan people which is beneficial to the British Army effort there.
Historian Tony Gould said Gurkhas have brought an excellent combination of qualities from a military point of view.
He said: "They are tough, they are brave, they are durable, they are amenable to discipline.
"They have another quality which you could say some British regiments had in the past, but it's doubtful that they have now, that is a strong family tradition.
"So that within each battalion there were usually very, very close family links, so when they were fighting, they were not so much fighting for their officers or the cause but for their friends and family."
Historically, Gurkhas who had served their time in the Army - a maximum of 30 years, and a minimum of 15 to secure a pension - were discharged back to Nepal.
But last year, all retired Gurkhas won the right to live in the UK, following a high-profile campaign led by actress Joanna Lumley, whose father served with the 6th Gurkha Rifles.
Gurkha veterans have also continued to fight for equal pensions with the soldiers they served alongside.
In 2007, they won a partial victory when pension rules were changed to give serving Gurkha soldiers equal pension rights with other service personnel in the UK.
But the British Gurkha Welfare Society said about 25,000 men who had retired before 1 July 1997 were denied the opportunity to transfer into UK armed forces pension schemes.
It said the government had acted unlawfully by paying them a third of the income of UK-based soldiers, and vowed to fight on.
A High Court test case in January 2010 ruled in favour of the Ministry of Defence, which argued the pension cut-off date was "justified and proportionate".
That decision has since been challenged by the Gurkhas, who have taken their battle to the Court of Appeal.