Though vIrashaiva is quite older sect of shaivism, very clear history of this path before the famous reformer of this tradition basavaNNa is not available. The source of its traditions trace back to the shivAgamas (1). Though it has spread all throughout bharata varsha with the mutts still in practice sticking to the vIrashaiva philosophy, it has been strong in karnataka and its surroundings. Though there are sanskrit and other language scriptures dedicated to vIrashaiva, the major part exist in kannaDa as vachana sAhitya (2).
The earliest reference to vIrashaiva occurs in the shivAgamas. Agamas while referring tot he types of shaivites like Adi shaiva etc, refers to vIrashaiva and tell about characteristics of vIrashaivites. Agamas deal elaborately on the basic principles of vIrashaiva like ShaDsthala, guru, linga, jangama etc. But shivAgamas do not talk exclusively about vIrashaivam. Like the case of vedas, shivAgamas are also looked up by various other shaivite paths. Each of the path may take in part or full the principles adapt and they evolve on that basis. That way vIrashaivam shares many points with the Agamas and has also evolved its specific style of elevating the souls.
It is not an easy task to attribute the vIrashaiva, like the bigger umbrella of sanAtana dharma itself, a single founder. But there are five acharyas who spread the knowledge of vIrashavam as the tradition claims. The five acharyas (3) starting from rENukAchArya originated the monasteries at five places spread across India rambhApuri (baLehaLLi), ujjaini, shrIshaila, kEdhAra, varanAsi. These mutts still continue the vIrashaiva traditions.
When told about vIrashaiva, the devotee who comes to mind first is basavaNNa. Lack of historical references to vIrashaivam before his period, major socio-spiritual facelift given during his period and the marvelous growth of the path subsequently makes one think that way. But the point that he got initiated into the path through a guru and the fellow devotees were also initiated to vIrashaiva probably indicate that, it may not be basavaNNa who founded this path. But without any doubt, it is he and the fellow devotees who made the major difference in the way the religion was flowing. Naturally he comes big in the mind of vIrashaivite.
Karnataka in the past had been stronghold of jainism and pAshupata - kAlAmukha shaivism. kAlAmukha shaivam (not to be confused with kApAlika) is supposed to have been quite following Agama tantras with less importance for caste etc. The indications are that this sect in karnAtaka influenced as well as merged itself into the gigantic vIrashaiva movement in later days.
vIrashaiva scholars (vachana composers) have been quite a bit influenced by the devotees of tamilnADu (4) like tirunyAna sambandhar and hold in high esteem the 63 devotees (5) as 63 purAtanaru, whom the Shaiva Siddhanta also holds in very high reverence. While shaivism in tamilnADu influenced vIrashaiva devotees to a great extent, in later days vIrashaivam spread in tamilnADu also. There are vIrashaiva mutts in many parts of tamilnADu and parts of vIrashaiva literature has been available in tamil for long time.
The practice of vIrashaivam which was in existence earlier too got a new outlook with the patronage of the great devotee basavaNNa and stood with splendor transforming the society in the later days.