Shaivism or Saivism is the name given to a group of religious traditions which regard Lord Shiva as the highest Supreme Self or Brahman and worship Him accordingly. It is considered to be one of the oldest, if not the oldest, sect of Hinduism, whose antiquity is said to be rooted in the prehistoric traditions of ancient India, dating back to the Indus Valley civilization (5000 BC) or even earlier.

Followers of Saivism are popularly known as Saivas or Saivites. The early Vedic Indians worshipped an aspect of Lord Shiva, known as Rudra, whom they both feared and revered. In the later Vedic period some Upanishads emerged, such as the Svetasvatara Upanishad and the Katha Upanishad, in which Lord Shiva was depicted as the highest Supreme Brahman. It was also the period during which the Vedic religion underwent a radical transformation where by Vaishnavism, Saivism and Shaktism rose to prominence and the ancient Vedic deities such as Brahma, Indra, Agni and Varuna yielded their place to Vishnu, Shiva and Shakti.

By the time the Puranas were composed, Lord Shiva was recognized as a part of Hindu Trinity and His worship became popular in many parts of the Indian subcontinent. Both the Ramayana and the Mahabharata mention Lord Shiva as a prominent Hindu god. Credit goes to the Saiva Puranas, which were composed mostly in the early Christian era, in making Saivism a popular religious sect. Of the 18 Puranas originally composed, six were Shaiva Puranas, namely Shiva Purana, Linga Purana, Matsya Purana, Kurma Purana, Skanda Purana and Agni Purana. The Agamas are the most authoritative works on Saivism. They deal with the methods of ritual worship and contemplation of Lord Shiva.

Many prominent rulers of ancient India such as the Kushanas, the Guptas, the BaraShivas, the Satavahanas and the Cholas were ardent worshippers of Shiva. The BaraShivas played an important role in preserving many ancient traditions of Saivism, at a time when Buddhism was on the rise. Apart from the Indian subcontinent, Shiva was also worshipped in other parts of the world such as Nepal, Sri Lanka, Malaysia, Singapore, Cambodia and Indonesia.

Lord Shiva's connection with ancient fertility cults is well documented. Followers of Shiva regard Him as the Father God and Shakti as the Mother Goddess. There are indications that the Indus people probably used fertility symbols resembling a prototype of the present day Shivalingam in their religious rituals. But we do not know whom they actually worshipped using the fertility symbols. The earliest archaeological evidence of Shivalingam dates back to 2nd Century BC. But we have reasons to believe that the practice was prevalent in ancient India centuries before that. Outwardly, the Shivalingam is a sexual symbol depicting the union of male and female genital organs. Symbolically it represents the involvement of the Soul and the Supreme Self with Nature or Prakriti.

There are many subsets with in Saivism. While they all acknowledge Lord Shiva as the Supreme Deity, they differ from one another in respect of other details such as the modes of worship, nature of Brahman, the nature of individual soul, the relationship between the two, the nature of reality and the means to liberation. These schools of Saivism primarily fall under one of the three schools of Hindu philosophy, namely Advaita (monism), Vishishtadvaita (qualified monism) and Dvaita (dualism). Of the few sects that survived the vicissitudes of time, the following five are the most prominent :-

 1. Pasupata Saivism

2. Kashmiri Saivism

3. Siddha Saivism

4. Gorakhnatha Saivism

5. Vira Saivism

 The Five Schools

1. Pasupata Saivism

2. Kashmiri Saivism

3. Siddha Saivism

4. Gorakhnatha Saivism

5. Vira Saivism

 Pasupata Saivism

The relationship between Shiva and Sakti outlined in the previous section holds in general terms for Saiva cults as well. The major distinguishing feature between Saktism and Saivism is the deity worshipped: Sakti for Saktas and Shiva for Saivas. As mentioned above, the term Shiva derives from the verb root si, which means 'to lie' and conveys a sense of Shiva as quiescent, though in the context of Saivism a more suggestive meaning is 'that in which all lies' which evokes a sense of Shiva as the all-pervasive supreme Reality. The term Shiva can also mean good, auspicious, gracious and other similar expressions as well as Lord, while Samkara is often cited as defining Shiva as 'one who purifies by the utterance of His name' or the 'Pure One' in the sense that Shiva is said to be unaffected by the three gunas (the three basic qualities or characteristics of creation: sattva - purity, light, harmony; rajas - activity, passion; tamas - dullness, inertia, ignorance).

In the company of Brahma as the creator of the cosmos and Visnu as its preserver, Shiva completes the Hindu trinity (the trimurti or three forms of Isvara or God in orthodox Hinduism) in the role of its destroyer. This role shouldn't be interpreted as something negative, though, as what Shiva destroys is the evil and suffering that must be cleared away for creation to follow. In Saivism the functions performed by Brahma and Visnu in the trimurti are incorporated into a broader conception of Shiva as the supreme Godhead who exercises five functions: creation (srsti), maintenance (sthiti), dissolution (samhara), obscuration (tirodhana) and grace (anugraha).

In his personal form Shiva is often portrayed as a yogi immersed in meditation wearing a tiger skin and holding a trident with snakes coiled around his arms and neck, all of which hold symbolic significance. Shiva is also depicted as Nataraja or Lord of the cosmic dance of creation and destruction, and is commonly represented by the Shiva-linga or lingam (meaning 'mark' or 'characteristic'), an oval-shaped mound made of stone, metal or clay with three horizontal stripes that is usually positioned on a yoni (meaning 'womb' or 'source') which acts as a pedestal. In this configuration the lingam and yoni symbolise the complementary relationship between the masculine and feminine principles of the cosmos respectively.

As with the beginnings of Tantra generally, the origins of Shiva worship are obscure, with the earliest evidence appearing in the Svetasvatara Upanisad, though there is mention of Shiva earlier still in the Rg Veda under the guise of the deity Rudra (from the verb root rud = 'to cry or howl'). Rudra appears as one of the 1,008 names of Shiva that are recited by Krsna to Yudhisthira in the Shiva Sahasranama, a section of the great Indian epic the Mahabharata. In the same division of that work there is another section, the Visnu Sahasranama (thousand names of Visnu), which is one of the most sacred and often chanted stotras (prayer or hymn) in Hinduism. The inclusion of both the Shiva and Visnu Sahasranamas in the Mahabharata documents their emerging significance as figures of worship, and pre-dates their increasing importance in the post- Christian era as both Saivism and Vaisnavism provided a Hindu alternative to Buddhism and Jainism.

Throughout its long history, Saivism produced an impressive array of lineages and traditions along with an extensive literature that includes the Saiva Agamas which, like the Sakta Tantras, are considered to be divinely revealed scriptures. The Saiva tradition recognises twenty-eight Agamas, though hundreds more are mentioned. As with the Tantras, the Agamas deal with a range of topics and develop a variety of philosophical positions, but all accept Shiva as the ultimate Reality and supreme Lord, and all agree on a small number of fundamental doctrines such as the threefold nature of pasa (literally 'rope') or the bonds that tie the individual to samsara: the impurities of ignorance (anava) and action (karma), and the power of obscuration (maya); and the four padas or stages of sadhana: virtuous conduct (carya), forms of religious worship (kriya), spiritual disciplines that have as their goal self-realisation (yoga), and liberating wisdom (jnana).

The multiplicity of philosophical positions, religious cultures and forms of sadhana that have developed around these points of agreement can most easily be discussed in terms of the major schools or sects of Saivism. However it should be kept in mind that only a well-informed minority knowingly subscribe to any particular school, with many if not most devotees of Shiva following an eclectic mix of beliefs and practices that form the religious observances of their families and communities. A representative selection of these sects would include Kashmir Saivism, Saiva Siddhanta, Kapalika, Vira Saivism and

Pasupata. Kashmir Saivism and Shiva Siddhanta are two of the better documented of these and so will be discussed in more detail in the following sections.

The Kapalikas are a fiercely ascetic and eccentric sect that worships the fearsome aspect of Shiva in the form of Bhairava the ferocious. The term kapalika means 'skull bearer' and in this context refers to the characteristic Kapalika practice of carrying a human skull as a begging and food bowl. Some also link the Kapalikas with devotion to Lord Shiva in the form of the supreme begger who is depicted as wearing nothing but a garland of skulls and ash from funeral pyres. The Kapalikas are sometimes confused with another eccentric Saiva sect the Aghoris, which some believe split off from the Kapalikas in the fourteenth century CE. Aghoris are notorious for living in cremation grounds, smearing themselves with ash from burnt corpses, meditating while seated on corpses, and even eating the flesh of these. These practices are consistent with the Aghori's strongly non-dualistic metaphysics and are designed to subvert conventional Hindu distinctions such as those between purity and impurity. If all distinctions are ultimately illusory, as non-dualism implies, then this truth can be realised by transcending social taboos and embracing even the most culturally marginal aspects of life.

Vira Saivism accepts a version of qualified non-dualism referred to as sakti vishishtadvaita which recognises both the difference and non-difference of Shiva and the jiva somewhat like the relationship between the sun and its rays. Shiva and His Sakti are held to be ultimately non-different and the world is accepted as real and not illusory, however Shiva is considered to be more than His creation, being both the efficient and material cause of the cosmos.

Pasupata is the earliest known Saiva sect and is thought to have been founded by Lakulisa in the first or second century CE. Pasupatas worship Shiva as Pasupati, Lord of individuals and animals (from pasu meaning individual soul or animal, and pati which means Lord as well as being another name for Shiva). This school accepts a version of the bhedabheda doctrine or the relation of identity in difference. For the Pasupatas this means that Shiva as the ultimate reality is both non-dual (abheda) and the personal Lord of all pasu or individuals. This implies a difference (bheda) between Pati and pasu that remains even after liberation which is nonetheless understood as a state of complete union with Shiva, and is sometimes compared to stars disappearing in the sky at dawn.