Short answers, pulled from the story.
The formation of Śaiva traditions begins to occur during the period from 200 BC to 100 AD. The earliest evidence for sectarian Rudra-Shiva worship appears with the Pasupata movement in early centuries CE.
Archaeological seals from the Indus Valley Civilisation dating to roughly 2500 BCE depict a figure seated in a meditative yoga pose surrounded by animals. Early scholars labeled this artifact the Pashupati seal and interpreted it as a prototype of Shiva.
Lingayatism founded by 12th-century philosopher Basava constitutes a distinct Shaivite religious tradition in India. Adherents wear an Ishtalinga necklace containing the linga symbol of Shiva.
Shaivism arrived in southeast Asia from south India reaching major islands including Sumatra Java and Bali between 400 and 700 CE. In Indonesia temples at archaeological sites suggest Shiva was highest god co-existing with Buddhism until about 1500 CE when Islam replaced both traditions.
Unlike Shankara's Advaita Vedanta, Shaiva monist schools consider Maya as Shakti or creative primordial power. The Pratyabhijna philosophy developed by 10th century scholar Utpaladeva and 11th century Abhinavagupta became central to this framework.