It will never be possible to define and certainly even more complicated to understand what Caste System really means. While it is a very complex social code it also is unwritten law of the Hindu Religion based entirely upon tradition and supported by various orthodox books held by Brahmin priests.
Entire Hindu Society, or the Brahminic Society has divided human-kind into four categories; namely the Brahmins, the Kshattriyas, the Vaisyas and the Sudras. These four classes of people are born in their already pre-determined families and cannot be changed under any circumstances and this explains why a non-Hindu may not be converted to Hinduism; for a convertee can never be a priest nor would he or she accept the life of a menial.
The Brahmins are the priestly class and they alone are the keepers of the religious books where these rules are written defining their place in society. They consider themselves pure and holy and must be born of Brahmin parents. Only 5% or less population of India belongs to this class yet this small percentage somehow manages total control over the psyche of Hindu population.
The Kshattriyas are the second in the order of preference; they are generally believed to belong to the ruling, princely class of society, and are classified as martial class, but most of them today are land owners and farmers and they too need to be born in the family of kshattriyas. Roughly, 25% of Indian population falls in this category.
The Vaisyas are the third category of the Hindu Society and include the farmers and the traders of the society and therefore, are the most numerous with about 60% of Indian population. Although, the Vaisyas are the business owners and are normally financially well off, they have little to do with actual farming of the land even though they too are categorized as Vaisyas. It is therefore, important to note that in strict sense no inter-marriage takes place between the two; farmers and traders.
The Sudras are the lowest class of people and are generally considered as menial or servant class of people. They are the poorest of the poor and consist of 30% of mostly uneducated Indian population. There is a misconception, a disinformation perhaps, perhaps spread at the behest of the upper class that the Sudras are the descendants of the population whose forebears were defeated and enslaved by the brahmins. It could have been so, except that ethnically the Brahmins and the Sudras look very much alike and bear same skin colour.
During the Raj Era, the British took advantage of this belief system and divided Indian Empire conveniently into two classes, i.e., martial and non-martial race. The Gurkhas were not only declared a martial race, they were made the elite of the elite, so much so, that whenever the British Indian Army was on ceremonial parade, the Gurkhas were always in the lead as they carried the Queens Truncheon which took precedence over rest of the Regimental Colours carried by British Indian Army.
Since gaining Independence, the Government of India have created one more caste of people and they are called Scheduled Tribe; they are held to be outside the Hindu Culture. The entire tribal people of North East India including Garo, Khasi, Mizo, Naga and all the aborigines tribes from rest of India fall in this category. The Gurkhas in India have now been granted the status of Scheduled Tribe, in other words the Gurkhas are now considered to exist outside the pale of Hinduism.
In the picture above can be seen HM The Queen inspecting the Truncheon. The historical account of the Queen’s Truncheon can be found elsewhere in this website.