Historical development of Shiva

He worship of Shiva is a pan-Hindu tradition, practiced widely across all of India, Nepal and Sri Lanka. Some historians believe that the figure of Shiva as we know him today was built up over time, with the ideas of many regional sects being amalgamated into a single figure. How the persona of Shiva converged as a composite deity is not well documented. Axel Michaels explains the composite nature of Shaivism as follows:

Like Vişņu, Śiva is also a high god,
who gives his name to a collection of theistic trends and sects: Śaivism.
Like Vaişņavism, the term also implies a unity which cannot be clearly found either in religious practice or in philosophical and esoteric doctrine.
Furthermore, practice and doctrine must be kept separate.

An example of assimilation took place in Maharashtra, where a regional deity named Khandoba is a patron deity of farming and herding castes. The foremost center of worship of Khandoba in Maharashtra is in Jejuri. Khandoba has been assimilated both as a name for Karttikeya and also as a form of Shiva himself , in which case he is worshipped in the form of a lingam. Khandoba's varied associations also include an identification with Surya.

The Pashupati seal
A seal discovered during the excavation of Mohenjo-daro has drawn attention as a possible representation of a "proto-Shiva" figure. This Pashupati (Lord of animal-like beings) seal shows a seated figure, possibly ithyphallic, surrounded by animals. Sir John Marshall and others have claimed that this figure is a prototype of Shiva and have described the figure as having three faces seated in a "yoga posture" with the knees out and feet joined. However, this claim is not without its share of critics, with some academics like Gavin Flood and John Keay characterizing them as unfounded.

Rudra
Shiva as we know him today shares many features with the Vedic god Rudra , and both Shiva and Rudra are viewed as the same personality in a number of Hindu traditions. Rudra, the god of the roaring storm, is usually portrayed in accordance with the element he represents as a fierce, destructive deity.

The oldest surviving text of Hinduism is the Rig Veda, which is dated to between 1700 and 1100 BCE based on linguistic and philological evidence. A god named Rudra is mentioned in the Rig Veda. The name Rudra is still used as a name for Shiva. In RV 2.33, he is described as the "Father of the Maruts", a group of storm gods. Furthermore, the Rudram, one of the most sacred hymns of Hinduism found both in the Rig and the Yajur Vedas and addressed to Rudra, invokes him as Shiva in several instances, but the term Shiva is used as a epithet for Indra, Mitra and Agni many times.

The identification of Shiva with the older god Rudra is not universally accepted, as Axel Michaels explains:

To what extent Śiva's origins are in fact to be sought in Rudra is extremely unclear. The tendency to consider Śiva an ancient god is based on this identification, even though the facts that justify such a far-reaching assumption are meager.

Rudra is called "The Archer" (Sanskrit: Śarva), and the arrow is an essential attribute of Rudra. This name appears in the Shiva Sahasranama, and R. K. Sharma notes that it is used as a name of Shiva often in later languages. The word is derived from the Sanskrit root śarv-, which means "to injure" or "to kill", and Sharma uses that general sense in his interpretive translation of the name Śarva as "One who can kill the forces of darkness". The names Dhanvin ("Bowman") and Bāṇahasta ("Archer", literally "Armed with arrows in his hands") also refer to archery.


Identification with Vedic deities
Shiva's rise to a major position in the pantheon was facilitated by his identification with a host of Vedic deities, including Agni, Indra, Prajāpati, Vāyu, and others.

Agni
Rudra and Agni have a close relationship. The identification between Agni and Rudra in the Vedic literature was an important factor in the process of Rudra's gradual development into the later character as Rudra-Shiva. The identification of Agni with Rudra is explicitly noted in the Nirukta, an important early text on etymology, which says, "Agni is called Rudra also." The interconnections between the two deities are complex, and according to Stella Kramrisch:

The fire myth of Rudra-Śiva plays on the whole gamut of fire, valuing all its potentialities and phases, from conflagration to illumination.

In the Śatarudrīa, some epithets of Rudra, such as Sasipañjara ("Of golden red hue as of flame") and Tivaṣīmati ("Flaming bright"), suggest a fusing of the two deities. Agni is said to be a bull, and Lord Shiva possesses a bull as his vehicle, Nandi. The horns of Agni, who is sometimes characterized as a bull, are mentioned. In medieval sculpture, both Agni and the form of Shiva known as Bhairava have flaming hair as a special feature.

Indra
The Indologist Koenraad Elst proposes that Shiva of Puranic Hinduism is a continuation of the Vedic Indra. He gives several reasons for his hypothesis. Both Shiva and Indra are known for having a thirst for Soma. Both are associated with mountains, rivers, male fertility, fierceness, fearlessness, warfare, transgression of established mores, the Aum sound, and the Supreme Self. In the Rig Veda, the term śiva is used to refer to Indra.

Indra, like Shiva, is likened to a bull. In the Rig Veda, Rudra is the father of the Maruts, but he is never associated with their warlike exploits as is Indra. In the present form of Hinduism, Indra and Shiva are considered as distinct deities.

by http://wapedia.mobi/en/Shiva