Were there any Sanyasi's in our ancient history prior to Jagadguru Sankaracharya? Can someone provide references of one existing in the B.C period who are as famous as Jagadguru Sankaracharya who provided Kanakadhara Sthotram at an age of around 5 years?
To distinguish the original Sankaracharya from others (The heads of the Sankara maths are given the title Sankaracharya) he is referred to Adi-Sankara.
Adi-Sankara is traditionally thought to have established four maths, at Sringeri, Dwarka, Badari, and Puri; but this has been a source of contention among historians. The orders of Dasanami Sannyasins hold their allegiances to these four maths, but the four maths do not have any control or affiliation over the orders. Puris, Bharatis, and Saraswathis Sannyasins are aligned with the Sringeri Math. Giris, Aranyas, and Vanas Sannyasins are aligned with the Jyoti Math. Ashramas and Tirthas Sannyasins are aligned with the Dwaraka Math. Parvatas and Sagaras Sannyasins are aligned with the Puri Math. It is not known whether the Dasanami orders came into existence at the time of Adi-Sankara or at a later date. It has been the Dasanami Sannyasins that have spread the popularity of Advaita and sannyas more so than the four maths.
Adi-Sankara himself received sannyas. Sannyas is one of the four asramas, stages, of life described in the Vedas (brahmacharya, garhasthya, vanaprastha, and sannyas). People have been taking to sannyas for thousands of years, it was not new to Adi-Sankara. Sannyas is taught in the Brahma Sutras (3.4.17) as well as the Upanishads (Brhadaranyaka Upanishad 4.4.22, Mundaka Upanishad 1.2.11, and Chhandogya Upanishad 5.10.1) and the Gita (VI. 1., and XVIII. 2.)
A sannyas who lived in the B.C. period as famous as Adi-Sankara? - the man who came to be known as the Buddha.