The Gorkhas live in the mountain ares of Nepal and neighboring states of India. They speak a dialect of Rajasthani and are said to be desended from Rajputs. Their population in Nepal is 11 million and comprise 50% of Nepal's population, and there are 10 million who are Indian.
Here's a good article on Gurkhas serving in Singapore. Its Singapore-centric, but provides a good introduction to the Gurkhas and their history and customs:
Hindu Warriors Guard Singapore From Terror
(Reuters) 18 April 2002
by Maria Golovnina
These days, Nepalese not Singaporeans guard some of the city's most sensitive sites. Gurkha soldiers, widely regarded as the most fearsome fighters in the world, are on the front line in the city-state as Singapore clamps down on Islamic militancy in the wake of the September 11 attacks on the United States. The Hindu warriors, raised in the foothills of the Himalayas and recruited by the Singapore police, have seldom been in the public eye here although their contingent has been based on the wealthy island for more than 50 years.
In the 1950s and 1960s, Gurkhas helped quell racial riots, strikes and trades union disputes in Singapore and won praise for their ability to bring calm and be impartial in any dispute.
Such turbulent times are long gone in Singapore but with tension high in the wake of the September attacks and the discovery of a plot to attack targets in Singapore, the Gurkhas are replacing local policemen at some of Singapore's most sensitive buildings.
These include the U.S. embassy and the American Club both the target of a foiled bombing plot by a regional Islamic group as well as the huge Jurong island petrochemical complex and Changi international airport.
"I think it's right to say that the Gurkhas, as part of the Singapore Police Force, have become more important here after September 11," said Commander Bruce M. Niven, head of the Gurkha Contingent in Singapore.
The Gurkhas' main strength is their impartiality in the multiracial city-state of four million people.
"In the local context, impartiality is one of their unique attributes," Niven said.
"Not being influenced by the local scene is part of their concept in Singapore. They just don't get emotionally involved in anything they may get caught up in."
It is the absence of political or religious roots in Singapore that has granted the soldiers a reputation of utmost objectivity -- key to success in Singapore which is inhabited by ethnic Chinese, Malay and Indian communities.
On A Knife Edge
The Gurkha Contingent was officially created in Singapore in 1949 from ex-British Army Gurkhas.
The city state has expanded the Contingent in the past few years according to a source with knowledge of the Gurkhas, but the events of September 11 could result in further increases.
"Before, you just never saw them on the streets (of Singapore)," said the source, who did not want to be identified.
"But the government is pushing them more into the public domain, which is a very interesting phenomenon."
The recent arrests of Islamic militants suspected of plotting bomb attacks have cast a shadow over the security-conscious island republic.
"We are a police force and we respond to what our republic requires of us in times of peace or in time of tension in the world," Niven said.
"We are unique here in the sense that our Gurkhas are police officers... While a soldier is perhaps out there to kill people, Gurkhas here are essentially present to maintain the peace, and protect people and property."
Yet, a Gurkha cop is still a Gurkha. According to legend, once his kukri dagger has been drawn in battle, it must "taste blood". If it has not, its master has to cut himself before returning it to its sheath.
Descended from the Rajputs tribes of North India, Gurkhas conquered the small Nepali region of Gorkha after being forced out from India in the early 16th century. Settling down in their new home, the called themselves Gurkhas.
A City in a City
From there, Gurkhas have travelled widely, serving the British empire in many parts of Asia but particularly Singapore and Hong Kong.
The Gurkha Cantonment in Singapore is like another world, with its own shops, schools and playgrounds.
"This is a small township, and I am like a mayor," Niven said.
Stationed in Singapore on a temporary mission, the Gurkhas do not sink deep roots into the city's soil. They are not allowed to.
The principle of impartiality forbids them to marry Singaporean women.
Most end up returning home to their villages in the hills where most people grow rice and wheat.
So far only two or three of them have broken the tradition and chosen to stay in Singapore instead of returning to Nepal, one of the world's poorest countries and torn by a six-year-old Maoist rebellion that has claimed some 3,500 lives.
Niven said they are mainly recruited from the Hindu and Buddhist villages and begin their careers at the age of 18 to 22.