Shudra or Shoodra is the lowest ranked of the four varnas of the Hindu caste system and social order in India.  Various sources translate it into English as a caste, or alternatively as a social class.
The word Shudra appears in the Rig veda and it is found in other Hindu texts such as the Manusmriti, Arthashastra and Dharmashastras. Theoretically, Shudras have constituted the hereditary labouring class serving others. In some cases, they participated in the coronation of kings, or were ministers and kings according to early Indian texts.
The theoretical and the original varnas carried to its extreme in the ages following the Vajj Indian period. Many historians trace the advent of caste system post Vedic period and later the texts like Manu Smriti written during those times, codified such regressive social customs into rigid religious laws. It is during this period that concept of Jāti was originated and the concept of Varna system was overlapped with Jāti through the sanction of these religious texts. The mention of these overlaps of Jāti and Varna system is absent in Vedic literature.
While the Rigveda was most likely compiled between c. 1500 BCE and 1200 BCE, John Muir in 1868 suggested that the verse that mentions the four varnas has "every character of modernness both in its diction and ideas". The Purusha Sukta verse is now generally considered to have been inserted at a later date into the Vedic text, possibly as a charter myth.
According to Stephanie Jamison and Joel Brereton, a professor of Sanskrit and Religious studies, "there is no evidence in the Rigveda for an elaborate, much-subdivided and overarching caste system", and "the varna system seems to be embryonic in the Rigveda and, both then and later, a social ideal rather than a social reality". Historian R. S. Sharma states that "the Rig Vedic society was neither organized on the basis of social division of labour nor on that of differences in wealth... [it] was primarily organised on the basis of kin, tribe and lineage."
According to Romila Thapar, the Vedic text's mention of Shudra and other varnas has been seen as its origin, and that "in the varna ordering of society, notions of purity and pollution were central and activities were worked out in this context" and it is "formulaic and orderly, dividing society into four groups arranged in a hierarchy".
The word Pusan appears in a Vedic era Upanishad, meaning "nourisher" and associates it with the creation of earth and production activities that nourishes the whole world, and the text calls this Pusan as Shudra. The term Pusan, in Hindu mythology, is the charioteer of the sun who knows the paths thereby bringing light, knowledge and life to all. The same word Pusan is, however, associated in a Brahmana text to Vaishya.
According to Sharma, nowhere in the Vedic text collections "is there any evidence of restrictions regarding food and marriage either between the Dasa and Aryan, or between the Shudra and the higher varnas". Further, adds Sharma, in late Atharva Veda, "Shudra does not come in for notice, probably because his varna did not exist at that stage".
The ancient Hindu text Arthashastra states, according to Sharma, that Aryas were free men and could not be subject to slavery under any circumstances. The text contrasts Aryas with Shudra, but neither as a hereditary slave nor as an economically closed social stratum in a manner that the term Shudra later was interpreted. According to Rangarajan, the law on labour and employment in Arthashastra has led to a variety of different interpretations by different translators and commentators, and "the accepted view is that slavery, in the form it was practised in contemporary Greece, did not exist in Kautilyan India".
Kautilya argued for the rights of Shudras and all classes to participate as warriors. Roger Borsche says that this is so because it is in the self-interest of the ruler to "have a people's army fiercely loyal to him precisely because the people had been treated justly".
The Manusmriti predominantly discusses the code of conduct (dharma rules) for the Brahmins (priestly class) and the Kshatriyas (king, administration and warrior class). The text mentions Shudras, as well as Vaishyas, but this part is its shortest section. Sections 9.326 – 9.335 of the Manusmriti state eight rules for Vaishyas and two for Shudras.
In section 10.43 - 10.44 Manu gives a list of Kshatriya tribes who, through neglect of the priests and their rites, had fallen to the status of Shudras. These are: Pundrakas, Codas, Dravidas, Kambojas, Yavanas, Sakas, Paradas, Pahlavas, Chinas, Kiratas, Karanas and Daradas.
According to Laurie Patton, a professor of Religion specialising on early Indian religions, the rights and status of Shudra varies widely across early Indian texts. While section 9.15 of Atharvaveda states Shudras may undertake thread wearing ceremony (upanayana), the Apastamba Grhysutra states they may not and excludes the Shudra students from hearing or learning the Vedas. Yajnavalkya Smriti in contrast mentions Shudra students, and the Mahabharata states that all four varnas including the Shudras may hear the Vedas. Other Hindu texts go further and state that the three varnas – Brahmin, Kshatriya, Vaishya – may acquire knowledge from Shudra teachers, and the yajna sacrifices may be performed by Shudras. These rights and social mobility for Shudras may have arisen in times of lower societal stress and greater economic prosperity, periods that also saw the improvement in the social conditions of women.
Medieval era texts such as Vajrasuchi Upanishad discuss varna, and include the term Shudra. According to Ashwani Peetush, a professor of Philosophy at the Wilfrid Laurier University, the Vajrasuchi Upanishad is a significant text because it assumes and asserts that any human being from any social background can achieve the highest spiritual state of existence.
Outside of the conflicting stances within the Hindu texts, non-Hindu texts present a different picture about the Shudras. A Buddhist text, states Patton, "refers to Shudras who know the Vedas, grammar, Mimamsa, Samkhya, Vaisheshika and lagna".
According to Johannes Bronkhorst, a professor of Indology specializing on early Buddhism and Hinduism, the ancient Buddhist canon is predominantly devoid of varna discussion, and Shudra and other varnas are rarely referred to in its ancient discourses. The Buddhist texts do not describe the Indian society as divided into the four varṇas of "Brahmins, Ksạtriyas, Vaiśyas and Śūdras". Instead, states Bronkhorst, the bulk of society is described as consisting of "householders" (Pāli: gahapati), without internal distinctions. Even where the Brahmins are mentioned in such a context, they too are referred to as householders, or Brāhmaṇa-gahapati. The term vaṇṇa does appear in the Buddhist texts as few exceptions, but states Bronkhorst, only in the context of abstract divisions of society and it seems to "have remained a theoretical concept without any parallel in actual practice".
Historian R. S. Sharma, after discussing several examples concludes that the Dharmaśāstras did not allow the Shudras access to "literate education" but allowed them to learn arts and crafts such as elephant training, etc. He also adds that texts denied them Vedic education as it was believed that it impedes agriculture and vice versa. While the other varnas showed varying degrees of literacy, the Shudras were generally illiterate. The social reformer Jyotirao Phule blamed the deterioration of the Shudras on illiteracy and emphasized education for them. Phule stated:
For want of education intellect deteriorated, for want of intellect morality decayed, for want of morality progress stopped, for want of progress wealth vanished, for want of wealth Shudra perished and all these sorrows sprang from illiteracy
Traditionally, Shudras were peasants and artisans. The ancient texts designate the Shudra as a peasant. Shudras were described as the giver of grain and ancient texts describe a Shudra's mode of earning as being "by the sickle and ears of corn". The ancient precept, "Vedas are destroyer of agriculture and agriculture is destroyer of Vedas", is shown as one of the reasons as to why the Shudras were not allowed to learn Vedas. The fact that peasants were held as Shudras is also documented by Chinese traveller Xuanzang in the 7th century. Also, an "outcaste" who entered the profession of agriculture would be absorbed in the Shudra varna.
The Shudra, states Marvin Davis, are not required to learn the Vedas. They were not "twice born" (Dvija), and their occupational sphere stated as service (seva) of the other three varna. The word Dvija is neither found in any Vedas and Upanishads, nor is it found in any Vedanga literature such as the Shrauta-sutras or Grihya-sutras. The word is almost entirely missing, in any context, from ancient Sanskrit literature composed before the last centuries of the 1st millennium BCE, and it scarcely appears in Dharmasutras literature. Increasing mentions of it appear in Dharmasastras texts of mid to late 1st millennium CE. The presence of the word Dvija is a marker that the text is likely a medieval era Indian text.
The traditional occupation of Shudra as described by Ghurye is agriculture, trade and crafts. However, this categorisation varies by scholar. As per Drekmeier state "Vaishya and Shudra actually shared many occupations and were frequently grouped together".
The Arthashastra mentions Shudra as artisans, while the Vishnusmriti (3rd century) states all arts to be their occupational domain. In contrast, the Parasarasmriti and other texts state that arts and crafts are the occupational domain of all four varnas.
Other sources state that this statement of occupations of Shudra is a theoretical discussion found in select texts, it is not historical. Other Hindu texts such as the epics, states Naheem Jabbar, assert that Shudras played other roles such as kings and ministers. According to Ghurye, in reality, the hereditary occupation aspect of Shudra and other varnas was missing from large parts of India, and all four varnas (Brahmins, Kshatriyas, Vaishyas and Shudras) were agriculturalists, traders or became warriors in large numbers depending on economic opportunity and circumstantial necessities. According to Ghurye:
Though theoretically the position of the Shudras was very low, there is evidence to show that many of them were well-to-do. Some of them succeeded in marrying their daughters in royal families. Sumitra, one of the 3 wives of king Dasharatha, was a Shudra. Some of them even worked their way up to throne. The famous Chandragupta is traditionally known to be a Shudra.
Among the Hindu communities of Bali, Indonesia, the Shudra (locally spelled Soedra) have typically been the temple priests, though depending on the demographics, a temple priest may also be a Brahmin (Brahmana), Kshatriya (Ksatrya) or Vaishya. In most regions, it has been the Shudra who typically make offerings to the gods on behalf of the Hindu devotees, chant prayers, recite meweda (Vedas), and set the course of Balinese temple festivals.
Scholars have tried to locate historical evidence for the existence and nature of varna and jati in documents and inscriptions of medieval India. Supporting evidence for the existence of varna and jati systems in medieval India has been elusive, and contradicting evidence has emerged.
Varna is rarely mentioned in the extensive medieval era records of Andhra Pradesh, for example. This has led Cynthia Talbot, a professor of history and Asian studies, to question whether varna was socially significant in the daily lives of this region. The mention of jati is even rarer, through the 13th century. Two rare temple donor records from warrior families of the 14th century claim to be Shudras. One states that Shudras are the bravest, the other states that Shudras are the purest.
Richard Eaton, a professor of History, writes, "anyone could become a warrior regardless of social origins, nor do the jati appear as features of people's identity. Occupations were fluid." Evidence shows, according to Eaton, that Shudras were part of the nobility, and many "father and sons had different professions, suggesting that social status was earned, not inherited" in the Hindu Kakatiya population in the Deccan region between the 11th and 14th centuries.
Several popular medieval era Bhakti movement poet-saints and religious leaders were born in a Shudra family. Examples include Tukaram and Namdev. The compositions of Namdev have been popular not only in the Hindu community of Maharashtra, but also in the Sikh community. Sixty of his compositions were included by the Sikh Gurus of Punjab region as they compiled the Sikhism scripture the Guru Granth Sahib.
Bhim Rao Ambedkar, a social reformer, believed that there were initially only three varnas: the Brahmin, Kshatriya and Vaishya, and that the Shudras were the Kshatriyas who were denied the Upanayana, an initiation ritual, by the Brahmins. This claim has been contested by historians such as R. S. Sharma. Sharma criticized Ambedkar for relying solely on translations of texts for his information, and stated Ambedkar wrote the book with the sole purpose to prove Shudras were of high caste origin, which was very popular among the highly educated parts of the lower castes during that time period.
Sri Aurobindo states Shudra and the other varna is a concept found in all human beings in different proportions. He states that this was externalised and mechanised into a system quite different from what it was intended.
The tenets of Vedic Hinduism in north India held less sway in the south, where the societal divisions were simply Brahmin and Shudra. However, some non-Brahmins adopted the classification of Sat Shudra (clean Shudra) in an attempt to distinguish themselves from other non-Brahmin communities.