Singh (सिंह sinh, ਸਿੰਘ singh, સિંહ sinh) is derived from the Sanskrit word Siṃha meaning "lion". It is a common title, middle name or surname in North India originally used by Hindu Rajputs and later adopted by the Sikhs although in present times it has also been adopted by other Hindu groups which may have affinity to other castes not directly falling within these two by mainly those who trace their origins to Kshatriya Rajput ancestors as the religious and customary use of this hereditary title or middle name has been specifically the exclusive privilege of the Hindu royal/aristocratic/warrior caste under the traditional Hindu caste system of Varnas and Jāti.
Strictly speaking Singh emerged as a hereditary title to be used as ones middle name signifying Royal/aristocratic/warrior status and family breeding in traditional Indian society where occupations were hereditary and families were only allowed to marry within the same occupation under the strict Hindu caste system. Singh thus has been used amongst Hindu Kshatriyas, mainly Rajputs who originally adopted it, their descendants within and out side their Royal/aristocratic/warrior caste and amongst decedents and followers of those Hindus who originally converted to Sikhism to help Guru Gobind Singh raise the army of Khalsa warriors in 1699, at the time Guru had asked all Hindu families from all Hindu castes in Punjab region to give their eldest sons to him to be baptized as Khalsa warriors and gave them the name Singh classifying them as warriors thus bringing equality amongst all his followers and removing any caste based discrimination, at the same time he named all baptized Khalsa Sikh women Kaur meaning princess for the same reason. The tradition for Hindus living in Punjab to have their eldest sons baptized as a Khalsa Sikh has continued till present times locally. The Sikh baptism ceremony is called Amrit Sanchar (or Khande di Pahul). Today with millions of baptized Sikhs residing all over India and around the world "Singh" and "Kaur" have become very common Sikh names with many using them as their last name and many others choosing to use them as their middle name with their original Hindu surname at the end.
The hereditary title Singh is only used as a last name where the use of the original family last name has become unpopular due to religious (as in the case of Sikhs) and customary practices (as in the case of those Rajputs who migrated out of their original homeland of Rajputana many hundred years ago and settled elsewhere where the use of Singh in their name was usually enough to denote that they belonged to Kshatriya royal/warrior caste and the local populace over the years started preferring to just call them Singh for short). However those who use Singh as their last name now and the elders in their family usually still do know their original family last name and "gotra" as it is still very much consulted by priests at the time of marriages as required by ancient Indian religious customs to ensure that families do not marry within the same extended clans to guard against the possible genetic consequences of inbreeding.
Today although Singhs still do prefer to join the Armed forces in India and elsewhere around the world where they have migrated to but in today's modern society with readily available higher education they have branched out in all professions and businesses. Any Caste System or Caste based discrimination is illegal in most countries including in India but due to its ancient roots embedded in the Indian society many or most people still continue to at least marry within the members of their original castes even though they may not any longer be practicing members of their caste's original occupation or social status. Singh today very much continues to be a hereditary title, middle name or last name passed down in Kahatriya Rajput and Sikh families and where intermarriages have happened, within their decedents in other castes and social groups. Like always it is still considered a matter of great pride to have it in one's name.
For male members of the Khalsa Sikhs it is mandatory to use Singh in their names as per religious requirements but those Kshatriyas and Rajputs not using it currently may adopt this title and middle name at any time or at the time of naming their children specially boys owing to them belonging to well recognized aristocratic caste as it being a title signifying aristocratic and warrior status of the family as per the traditional Hindu caste system and customs even though in these modern times the families using it may not be predominantly practicing warriors, enlisted members of Armed Forces at all or indeed excercising any of the rights of a local lord as would have been the case in times gone by.
Singh was first used as a surname by the Rajputs beginning in the 7th century. It has been common practice among the Rajput men to have Singh as their middle name. The Rajputs started using Singh in preference to the classical epithet of "Varman".
The Sikhs adopted Singh as a surname in 1699, as per the wish of Guru Gobind Singh, the tenth Sikh Guru. In the Spring of 1699, on the day of Baisakhi, Guru Gobind Singh (originally named Guru Gobind Rai), made it mandatory for all Sikh males to append the name suffix Singh after their name. Singh is used as a middle name or as a surname (see naming patterns section) by approximately 20 million adherents of Sikhism.
Apart from the Sikhs and the Rajputs, several other groups in India have also adopted Singh as either a middle name or a surname. Some of these include the Yadavs (e.g. "Mulayam Singh Yadav"), the Bhumihars, the non-Sikh Rajput Punjabis, the Gujjars (e.g. "Nirbhay Singh Gujjar"), and the non-Sikh Jats (e.g. "Maharaja Bhim Singh Rana").
The use of Singh in Hindus as a middle name or last name denotes automatically that they are from the Kshatriya varna and are of the Rajput sub-caste or are descended from them where intermarriages have happened with Jats and Gujjars etc.. Original occupation of Kshatriyas and Rajputs was of being warriors and rulers, many families under different circumstances over the centuries changed their profession to being farmers, or craftsmen such as carpenters, blacksmiths etc. with some eventually intermarrying within the Hindu castes usually practicing these professions but chose to retain Singh in their name denoting their ancestry and original family genealogy and caste.
Contrary to the popular belief that Singh is only used by Indian Punjabis (Rajput and Sikh), Singh is in fact used by a wider population from Punjab to Uttar Pradesh and from Kashmir down into Rajasthan, Madhya Pradesh and Maharastra to Nepal as well as the far eastern states of Manipur, Assam, Tripura, Sikkim and even Bhutan, spanning the entire subcontinent and even reaching Southeast Asia. It is also found in use among West Indians of Indian origin namely in places of Guyana, Trinidad and Surinam, as well as people of Indian origin found in Mauritius and Fiji Island because they trace their origins to one of the states in India where the name was in use by their Kshatriya Rajput ancestors.
Singh is often used the traditional way, as previously described, by having it as the middle name after the first name and followed by the clan/family name by many communities, groups & peoples. For example, "Yogendra Singh Yadav", "Bhupinder Singh Hooda", "Mahendra Singh Dhoni" and "Bhairon Singh Shekhawat"). Sikh examples include, "Jassa Singh Ahluwalia" (Supreme leader of the Khalsa army), "Jassa Singh Ramgarhia" & "Hari Singh Nalwa" (General of Khalsa army). Thus Singh can be used as a middle name before the individual's surname, a common practice among many groups in India e.g. Jassa Singh Ahluwalia (Pattern, 1: First Name, 2: Singh, 3: Family name).Sometimes, but less often in modern times, Singh is used as a surname (for example, "Manmohan Singh", "Vijay Singh" and "Harbhajan Singh").
Earlier, a common practice among the Rajput men was to have Kumar as their middle name and Singh as their last name, while Rajput women had the last name of Kumari or Kunwarani. However, many Rajput women have Singh in their name as well. Several times during history due to various reasons Rajputs have migrated out of Rajputana their native region; many of those that settled in other parts of India have since come to use Singh as their last name even though they belong to separate Rajput gotras and clans, this happened over several generations due to the local population preferring to popularly calling them just Singh in the new places they settled outside Rajputana, this was usually enough to denote that they belonged to the Kshatriya varna and were Hindu Rajput warriors by caste.
A section of around a million adherents of Sikhism that live abroad in western countries only keep Singh or Kaur as their last name. This has caused legal problems in immigration procedures especially in Canada with Canadian High Commission in New Delhi, India for a decade stating in letters to it's Sikh clients "the names Kaur and Singh do not qualify for the purpose of immigration to Canada" people with these common Sikh surnames have to change their last names before coming to Canada. This has been causing severe emotional, legal and financial hardship for Sikh applicants in India who have been complying by undergoing costly and lengthy name change procedures out of fear that their application to immigrate to Canada will be rejected outright otherwise. However as soon as the media got involved and after a storm of complaints from Sikhs, Citizenship and Immigration Canada, Ottawa reversed New Delhi office's 10-year decree that `the names Kaur and Singh do not qualify for the purpose of immigration to Canada' with Canadian Federal immigration officials further clarifying that "asking applicants to provide a surname in addition to Singh or Kaur has been an administrative practice used by our visa office in New Delhi as a way to improve client service and reduce incidents of mistaken identity. This was not a mandatory requirement. There is no policy or practice whereby people with these surnames are asked to change their names, the letters that were sent out to Sikh clients in Delhi were poorly worded.